Modularize commit-walker

This turns the extern functions to be provided by the backend into a
struct of pointers, renames the functions to be more
namespace-friendly, and updates http-fetch to this interface. It
removes the unused include from http-push.c. It makes git-http-fetch a
builtin (with the implementation a separate file, accessible
directly).

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Makefile b/Makefile
index 520f156f34d946e5b82479018dc0eafadf9677cd..3436a2326a3f98c5af86b009efb694a600147517 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -514,7 +514,9 @@ else
        CC_LD_DYNPATH = -R
 endif
 
-ifndef NO_CURL
+ifdef NO_CURL
+       BASIC_CFLAGS += -DNO_CURL
+else
        ifdef CURLDIR
                # Try "-Wl,-rpath=$(CURLDIR)/$(lib)" in such a case.
                BASIC_CFLAGS += -I$(CURLDIR)/include
@@ -522,7 +524,9 @@ ifndef NO_CURL
        else
                CURL_LIBCURL = -lcurl
        endif
-       PROGRAMS += git-http-fetch$X
+       BUILTIN_OBJS += builtin-http-fetch.o
+       EXTLIBS += $(CURL_LIBCURL)
+       LIB_OBJS += http.o walker.o http-walker.o
        curl_check := $(shell (echo 070908; curl-config --vernum) | sort -r | sed -ne 2p)
        ifeq "$(curl_check)" "070908"
                ifndef NO_EXPAT
@@ -884,7 +888,7 @@ http.o: http.c GIT-CFLAGS
        $(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DGIT_USER_AGENT='"git/$(GIT_VERSION)"' $<
 
 ifdef NO_EXPAT
-http-fetch.o: http-fetch.c http.h GIT-CFLAGS
+http-walker.o: http-walker.c http.h GIT-CFLAGS
        $(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DNO_EXPAT $<
 endif
 
@@ -893,16 +897,13 @@ git-%$X: %.o $(GITLIBS)
 
 git-imap-send$X: imap-send.o $(LIB_FILE)
 
-http.o http-fetch.o http-push.o: http.h
-git-http-fetch$X: fetch.o http.o http-fetch.o $(GITLIBS)
-       $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
-               $(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
+http.o http-walker.o http-push.o: http.h
 
 git-http-push$X: revision.o http.o http-push.o $(GITLIBS)
        $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \
                $(LIBS) $(CURL_LIBCURL) $(EXPAT_LIBEXPAT)
 
-$(LIB_OBJS) $(BUILTIN_OBJS) fetch.o: $(LIB_H)
+$(LIB_OBJS) $(BUILTIN_OBJS) walker.o: $(LIB_H)
 $(patsubst git-%$X,%.o,$(PROGRAMS)): $(LIB_H) $(wildcard */*.h)
 $(DIFF_OBJS): diffcore.h
 

diff --git a/builtin-http-fetch.c b/builtin-http-fetch.c
new file mode 100644 (file)
index 0000000..4a50dbd
--- /dev/null
+++ b/builtin-http-fetch.c
@@ -0,0 +1,77 @@
+#include "cache.h"
+#include "walker.h"
+
+int cmd_http_fetch(int argc, const char **argv, const char *prefix)
+{
+       struct walker *walker;
+       int commits_on_stdin = 0;
+       int commits;
+       const char **write_ref = NULL;
+       char **commit_id;
+       const char *url;
+       int arg = 1;
+       int rc = 0;
+       int get_tree = 0;
+       int get_history = 0;
+       int get_all = 0;
+       int get_verbosely = 0;
+       int get_recover = 0;
+
+       git_config(git_default_config);
+
+       while (arg < argc && argv[arg][0] == '-') {
+               if (argv[arg][1] == 't') {
+                       get_tree = 1;
+               } else if (argv[arg][1] == 'c') {
+                       get_history = 1;
+               } else if (argv[arg][1] == 'a') {
+                       get_all = 1;
+                       get_tree = 1;
+                       get_history = 1;
+               } else if (argv[arg][1] == 'v') {
+                       get_verbosely = 1;
+               } else if (argv[arg][1] == 'w') {
+                       write_ref = &argv[arg + 1];
+                       arg++;
+               } else if (!strcmp(argv[arg], "--recover")) {
+                       get_recover = 1;
+               } else if (!strcmp(argv[arg], "--stdin")) {
+                       commits_on_stdin = 1;
+               }
+               arg++;
+       }
+       if (argc < arg + 2 - commits_on_stdin) {
+               usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url");
+               return 1;
+       }
+       if (commits_on_stdin) {
+               commits = walker_targets_stdin(&commit_id, &write_ref);
+       } else {
+               commit_id = (char **) &argv[arg++];
+               commits = 1;
+       }
+       url = argv[arg];
+
+       walker = get_http_walker(url);
+       walker->get_tree = get_tree;
+       walker->get_history = get_history;
+       walker->get_all = get_all;
+       walker->get_verbosely = get_verbosely;
+       walker->get_recover = get_recover;
+
+       rc = walker_fetch(walker, commits, commit_id, write_ref, url);
+
+       if (commits_on_stdin)
+               walker_targets_free(commits, commit_id, write_ref);
+
+       if (walker->corrupt_object_found) {
+               fprintf(stderr,
+"Some loose object were found to be corrupt, but they might be just\n"
+"a false '404 Not Found' error message sent with incorrect HTTP\n"
+"status code.  Suggest running git-fsck.\n");
+       }
+
+       walker_free(walker);
+
+       return rc;
+}

diff --git a/builtin.h b/builtin.h
index 03ee7bf780be93601f9190b733984ad82951952b..1fa1444e33e3a687442d1fbab67cc9bdfacd2726 100644 (file)
--- a/builtin.h
+++ b/builtin.h
@@ -40,6 +40,7 @@ extern int cmd_gc(int argc, const char **argv, const char *prefix);
 extern int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix);
 extern int cmd_grep(int argc, const char **argv, const char *prefix);
 extern int cmd_help(int argc, const char **argv, const char *prefix);
+extern int cmd_http_fetch(int argc, const char **argv, const char *prefix);
 extern int cmd_init_db(int argc, const char **argv, const char *prefix);
 extern int cmd_log(int argc, const char **argv, const char *prefix);
 extern int cmd_log_reflog(int argc, const char **argv, const char *prefix);

diff --git a/fetch.c b/fetch.c
deleted file mode 100644 (file)
index 811be87..0000000
--- a/fetch.c
+++ /dev/null
@@ -1,317 +0,0 @@
-#include "cache.h"
-#include "fetch.h"
-#include "commit.h"
-#include "tree.h"
-#include "tree-walk.h"
-#include "tag.h"
-#include "blob.h"
-#include "refs.h"
-#include "strbuf.h"
-
-int get_tree = 0;
-int get_history = 0;
-int get_all = 0;
-int get_verbosely = 0;
-int get_recover = 0;
-static unsigned char current_commit_sha1[20];
-
-void pull_say(const char *fmt, const char *hex)
-{
-       if (get_verbosely)
-               fprintf(stderr, fmt, hex);
-}
-
-static void report_missing(const struct object *obj)
-{
-       char missing_hex[41];
-       strcpy(missing_hex, sha1_to_hex(obj->sha1));;
-       fprintf(stderr, "Cannot obtain needed %s %s\n",
-               obj->type ? typename(obj->type): "object", missing_hex);
-       if (!is_null_sha1(current_commit_sha1))
-               fprintf(stderr, "while processing commit %s.\n",
-                       sha1_to_hex(current_commit_sha1));
-}
-
-static int process(struct object *obj);
-
-static int process_tree(struct tree *tree)
-{
-       struct tree_desc desc;
-       struct name_entry entry;
-
-       if (parse_tree(tree))
-               return -1;
-
-       init_tree_desc(&desc, tree->buffer, tree->size);
-       while (tree_entry(&desc, &entry)) {
-               struct object *obj = NULL;
-
-               /* submodule commits are not stored in the superproject */
-               if (S_ISGITLINK(entry.mode))
-                       continue;
-               if (S_ISDIR(entry.mode)) {
-                       struct tree *tree = lookup_tree(entry.sha1);
-                       if (tree)
-                               obj = &tree->object;
-               }
-               else {
-                       struct blob *blob = lookup_blob(entry.sha1);
-                       if (blob)
-                               obj = &blob->object;
-               }
-               if (!obj || process(obj))
-                       return -1;
-       }
-       free(tree->buffer);
-       tree->buffer = NULL;
-       tree->size = 0;
-       return 0;
-}
-
-#define COMPLETE       (1U << 0)
-#define SEEN           (1U << 1)
-#define TO_SCAN                (1U << 2)
-
-static struct commit_list *complete = NULL;
-
-static int process_commit(struct commit *commit)
-{
-       if (parse_commit(commit))
-               return -1;
-
-       while (complete && complete->item->date >= commit->date) {
-               pop_most_recent_commit(&complete, COMPLETE);
-       }
-
-       if (commit->object.flags & COMPLETE)
-               return 0;
-
-       hashcpy(current_commit_sha1, commit->object.sha1);
-
-       pull_say("walk %s\n", sha1_to_hex(commit->object.sha1));
-
-       if (get_tree) {
-               if (process(&commit->tree->object))
-                       return -1;
-               if (!get_all)
-                       get_tree = 0;
-       }
-       if (get_history) {
-               struct commit_list *parents = commit->parents;
-               for (; parents; parents = parents->next) {
-                       if (process(&parents->item->object))
-                               return -1;
-               }
-       }
-       return 0;
-}
-
-static int process_tag(struct tag *tag)
-{
-       if (parse_tag(tag))
-               return -1;
-       return process(tag->tagged);
-}
-
-static struct object_list *process_queue = NULL;
-static struct object_list **process_queue_end = &process_queue;
-
-static int process_object(struct object *obj)
-{
-       if (obj->type == OBJ_COMMIT) {
-               if (process_commit((struct commit *)obj))
-                       return -1;
-               return 0;
-       }
-       if (obj->type == OBJ_TREE) {
-               if (process_tree((struct tree *)obj))
-                       return -1;
-               return 0;
-       }
-       if (obj->type == OBJ_BLOB) {
-               return 0;
-       }
-       if (obj->type == OBJ_TAG) {
-               if (process_tag((struct tag *)obj))
-                       return -1;
-               return 0;
-       }
-       return error("Unable to determine requirements "
-                    "of type %s for %s",
-                    typename(obj->type), sha1_to_hex(obj->sha1));
-}
-
-static int process(struct object *obj)
-{
-       if (obj->flags & SEEN)
-               return 0;
-       obj->flags |= SEEN;
-
-       if (has_sha1_file(obj->sha1)) {
-               /* We already have it, so we should scan it now. */
-               obj->flags |= TO_SCAN;
-       }
-       else {
-               if (obj->flags & COMPLETE)
-                       return 0;
-               prefetch(obj->sha1);
-       }
-
-       object_list_insert(obj, process_queue_end);
-       process_queue_end = &(*process_queue_end)->next;
-       return 0;
-}
-
-static int loop(void)
-{
-       struct object_list *elem;
-
-       while (process_queue) {
-               struct object *obj = process_queue->item;
-               elem = process_queue;
-               process_queue = elem->next;
-               free(elem);
-               if (!process_queue)
-                       process_queue_end = &process_queue;
-
-               /* If we are not scanning this object, we placed it in
-                * the queue because we needed to fetch it first.
-                */
-               if (! (obj->flags & TO_SCAN)) {
-                       if (fetch(obj->sha1)) {
-                               report_missing(obj);
-                               return -1;
-                       }
-               }
-               if (!obj->type)
-                       parse_object(obj->sha1);
-               if (process_object(obj))
-                       return -1;
-       }
-       return 0;
-}
-
-static int interpret_target(char *target, unsigned char *sha1)
-{
-       if (!get_sha1_hex(target, sha1))
-               return 0;
-       if (!check_ref_format(target)) {
-               if (!fetch_ref(target, sha1)) {
-                       return 0;
-               }
-       }
-       return -1;
-}
-
-static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
-{
-       struct commit *commit = lookup_commit_reference_gently(sha1, 1);
-       if (commit) {
-               commit->object.flags |= COMPLETE;
-               insert_by_date(commit, &complete);
-       }
-       return 0;
-}
-
-int pull_targets_stdin(char ***target, const char ***write_ref)
-{
-       int targets = 0, targets_alloc = 0;
-       struct strbuf buf;
-       *target = NULL; *write_ref = NULL;
-       strbuf_init(&buf);
-       while (1) {
-               char *rf_one = NULL;
-               char *tg_one;
-
-               read_line(&buf, stdin, '\n');
-               if (buf.eof)
-                       break;
-               tg_one = buf.buf;
-               rf_one = strchr(tg_one, '\t');
-               if (rf_one)
-                       *rf_one++ = 0;
-
-               if (targets >= targets_alloc) {
-                       targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
-                       *target = xrealloc(*target, targets_alloc * sizeof(**target));
-                       *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
-               }
-               (*target)[targets] = xstrdup(tg_one);
-               (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
-               targets++;
-       }
-       return targets;
-}
-
-void pull_targets_free(int targets, char **target, const char **write_ref)
-{
-       while (targets--) {
-               free(target[targets]);
-               if (write_ref && write_ref[targets])
-                       free((char *) write_ref[targets]);
-       }
-}
-
-int pull(int targets, char **target, const char **write_ref,
-         const char *write_ref_log_details)
-{
-       struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
-       unsigned char *sha1 = xmalloc(targets * 20);
-       char *msg;
-       int ret;
-       int i;
-
-       save_commit_buffer = 0;
-       track_object_refs = 0;
-
-       for (i = 0; i < targets; i++) {
-               if (!write_ref || !write_ref[i])
-                       continue;
-
-               lock[i] = lock_ref_sha1(write_ref[i], NULL);
-               if (!lock[i]) {
-                       error("Can't lock ref %s", write_ref[i]);
-                       goto unlock_and_fail;
-               }
-       }
-
-       if (!get_recover)
-               for_each_ref(mark_complete, NULL);
-
-       for (i = 0; i < targets; i++) {
-               if (interpret_target(target[i], &sha1[20 * i])) {
-                       error("Could not interpret %s as something to pull", target[i]);
-                       goto unlock_and_fail;
-               }
-               if (process(lookup_unknown_object(&sha1[20 * i])))
-                       goto unlock_and_fail;
-       }
-
-       if (loop())
-               goto unlock_and_fail;
-
-       if (write_ref_log_details) {
-               msg = xmalloc(strlen(write_ref_log_details) + 12);
-               sprintf(msg, "fetch from %s", write_ref_log_details);
-       } else {
-               msg = NULL;
-       }
-       for (i = 0; i < targets; i++) {
-               if (!write_ref || !write_ref[i])
-                       continue;
-               ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
-               lock[i] = NULL;
-               if (ret)
-                       goto unlock_and_fail;
-       }
-       free(msg);
-
-       return 0;
-
-
-unlock_and_fail:
-       for (i = 0; i < targets; i++)
-               if (lock[i])
-                       unlock_ref(lock[i]);
-       return -1;
-}

diff --git a/fetch.h b/fetch.h
deleted file mode 100644 (file)
index be48c6f..0000000
--- a/fetch.h
+++ /dev/null
@@ -1,54 +0,0 @@
-#ifndef PULL_H
-#define PULL_H
-
-/*
- * Fetch object given SHA1 from the remote, and store it locally under
- * GIT_OBJECT_DIRECTORY.  Return 0 on success, -1 on failure.  To be
- * provided by the particular implementation.
- */
-extern int fetch(unsigned char *sha1);
-
-/*
- * Fetch the specified object and store it locally; fetch() will be
- * called later to determine success. To be provided by the particular
- * implementation.
- */
-extern void prefetch(unsigned char *sha1);
-
-/*
- * Fetch ref (relative to $GIT_DIR/refs) from the remote, and store
- * the 20-byte SHA1 in sha1.  Return 0 on success, -1 on failure.  To
- * be provided by the particular implementation.
- */
-extern int fetch_ref(char *ref, unsigned char *sha1);
-
-/* Set to fetch the target tree. */
-extern int get_tree;
-
-/* Set to fetch the commit history. */
-extern int get_history;
-
-/* Set to fetch the trees in the commit history. */
-extern int get_all;
-
-/* Set to be verbose */
-extern int get_verbosely;
-
-/* Set to check on all reachable objects. */
-extern int get_recover;
-
-/* Report what we got under get_verbosely */
-extern void pull_say(const char *, const char *);
-
-/* Load pull targets from stdin */
-extern int pull_targets_stdin(char ***target, const char ***write_ref);
-
-/* Free up loaded targets */
-extern void pull_targets_free(int targets, char **target, const char **write_ref);
-
-/* If write_ref is set, the ref filename to write the target value to. */
-/* If write_ref_log_details is set, additional text will appear in the ref log. */
-extern int pull(int targets, char **target, const char **write_ref,
-               const char *write_ref_log_details);
-
-#endif /* PULL_H */

diff --git a/git.c b/git.c
index 56ae8ccccf6917fb27f74d56d7d96a9c4788cb54..41fe73eff9dd17d1b6bd7c92510870b5fd081e2d 100644 (file)
--- a/git.c
+++ b/git.c
@@ -344,6 +344,9 @@ static void handle_internal_command(int argc, const char **argv)
                { "get-tar-commit-id", cmd_get_tar_commit_id },
                { "grep", cmd_grep, RUN_SETUP | USE_PAGER },
                { "help", cmd_help },
+#ifndef NO_CURL
+               { "http-fetch", cmd_http_fetch, RUN_SETUP },
+#endif
                { "init", cmd_init_db },
                { "init-db", cmd_init_db },
                { "log", cmd_log, RUN_SETUP | USE_PAGER },

diff --git a/http-fetch.c b/http-fetch.c
deleted file mode 100644 (file)
index 7786110..0000000
--- a/http-fetch.c
+++ /dev/null
@@ -1,1059 +0,0 @@
-#include "cache.h"
-#include "commit.h"
-#include "pack.h"
-#include "fetch.h"
-#include "http.h"
-
-#define PREV_BUF_SIZE 4096
-#define RANGE_HEADER_SIZE 30
-
-static int commits_on_stdin;
-
-static int got_alternates = -1;
-static int corrupt_object_found;
-
-static struct curl_slist *no_pragma_header;
-
-struct alt_base
-{
-       char *base;
-       int got_indices;
-       struct packed_git *packs;
-       struct alt_base *next;
-};
-
-static struct alt_base *alt;
-
-enum object_request_state {
-       WAITING,
-       ABORTED,
-       ACTIVE,
-       COMPLETE,
-};
-
-struct object_request
-{
-       unsigned char sha1[20];
-       struct alt_base *repo;
-       char *url;
-       char filename[PATH_MAX];
-       char tmpfile[PATH_MAX];
-       int local;
-       enum object_request_state state;
-       CURLcode curl_result;
-       char errorstr[CURL_ERROR_SIZE];
-       long http_code;
-       unsigned char real_sha1[20];
-       SHA_CTX c;
-       z_stream stream;
-       int zret;
-       int rename;
-       struct active_request_slot *slot;
-       struct object_request *next;
-};
-
-struct alternates_request {
-       const char *base;
-       char *url;
-       struct buffer *buffer;
-       struct active_request_slot *slot;
-       int http_specific;
-};
-
-static struct object_request *object_queue_head;
-
-static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
-                              void *data)
-{
-       unsigned char expn[4096];
-       size_t size = eltsize * nmemb;
-       int posn = 0;
-       struct object_request *obj_req = (struct object_request *)data;
-       do {
-               ssize_t retval = xwrite(obj_req->local,
-                                      (char *) ptr + posn, size - posn);
-               if (retval < 0)
-                       return posn;
-               posn += retval;
-       } while (posn < size);
-
-       obj_req->stream.avail_in = size;
-       obj_req->stream.next_in = ptr;
-       do {
-               obj_req->stream.next_out = expn;
-               obj_req->stream.avail_out = sizeof(expn);
-               obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
-               SHA1_Update(&obj_req->c, expn,
-                           sizeof(expn) - obj_req->stream.avail_out);
-       } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
-       data_received++;
-       return size;
-}
-
-static int missing__target(int code, int result)
-{
-       return  /* file:// URL -- do we ever use one??? */
-               (result == CURLE_FILE_COULDNT_READ_FILE) ||
-               /* http:// and https:// URL */
-               (code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
-               /* ftp:// URL */
-               (code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
-               ;
-}
-
-#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
-
-static void fetch_alternates(const char *base);
-
-static void process_object_response(void *callback_data);
-
-static void start_object_request(struct object_request *obj_req)
-{
-       char *hex = sha1_to_hex(obj_req->sha1);
-       char prevfile[PATH_MAX];
-       char *url;
-       char *posn;
-       int prevlocal;
-       unsigned char prev_buf[PREV_BUF_SIZE];
-       ssize_t prev_read = 0;
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-       struct active_request_slot *slot;
-
-       snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
-       unlink(prevfile);
-       rename(obj_req->tmpfile, prevfile);
-       unlink(obj_req->tmpfile);
-
-       if (obj_req->local != -1)
-               error("fd leakage in start: %d", obj_req->local);
-       obj_req->local = open(obj_req->tmpfile,
-                             O_WRONLY | O_CREAT | O_EXCL, 0666);
-       /* This could have failed due to the "lazy directory creation";
-        * try to mkdir the last path component.
-        */
-       if (obj_req->local < 0 && errno == ENOENT) {
-               char *dir = strrchr(obj_req->tmpfile, '/');
-               if (dir) {
-                       *dir = 0;
-                       mkdir(obj_req->tmpfile, 0777);
-                       *dir = '/';
-               }
-               obj_req->local = open(obj_req->tmpfile,
-                                     O_WRONLY | O_CREAT | O_EXCL, 0666);
-       }
-
-       if (obj_req->local < 0) {
-               obj_req->state = ABORTED;
-               error("Couldn't create temporary file %s for %s: %s",
-                     obj_req->tmpfile, obj_req->filename, strerror(errno));
-               return;
-       }
-
-       memset(&obj_req->stream, 0, sizeof(obj_req->stream));
-
-       inflateInit(&obj_req->stream);
-
-       SHA1_Init(&obj_req->c);
-
-       url = xmalloc(strlen(obj_req->repo->base) + 51);
-       obj_req->url = xmalloc(strlen(obj_req->repo->base) + 51);
-       strcpy(url, obj_req->repo->base);
-       posn = url + strlen(obj_req->repo->base);
-       strcpy(posn, "/objects/");
-       posn += 9;
-       memcpy(posn, hex, 2);
-       posn += 2;
-       *(posn++) = '/';
-       strcpy(posn, hex + 2);
-       strcpy(obj_req->url, url);
-
-       /* If a previous temp file is present, process what was already
-          fetched. */
-       prevlocal = open(prevfile, O_RDONLY);
-       if (prevlocal != -1) {
-               do {
-                       prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
-                       if (prev_read>0) {
-                               if (fwrite_sha1_file(prev_buf,
-                                                    1,
-                                                    prev_read,
-                                                    obj_req) == prev_read) {
-                                       prev_posn += prev_read;
-                               } else {
-                                       prev_read = -1;
-                               }
-                       }
-               } while (prev_read > 0);
-               close(prevlocal);
-       }
-       unlink(prevfile);
-
-       /* Reset inflate/SHA1 if there was an error reading the previous temp
-          file; also rewind to the beginning of the local file. */
-       if (prev_read == -1) {
-               memset(&obj_req->stream, 0, sizeof(obj_req->stream));
-               inflateInit(&obj_req->stream);
-               SHA1_Init(&obj_req->c);
-               if (prev_posn>0) {
-                       prev_posn = 0;
-                       lseek(obj_req->local, 0, SEEK_SET);
-                       ftruncate(obj_req->local, 0);
-               }
-       }
-
-       slot = get_active_slot();
-       slot->callback_func = process_object_response;
-       slot->callback_data = obj_req;
-       obj_req->slot = slot;
-
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
-       curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-
-       /* If we have successfully processed data from a previous fetch
-          attempt, only fetch the data we don't already have. */
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of object %s at byte %ld\n",
-                               hex, prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl,
-                                CURLOPT_HTTPHEADER, range_header);
-       }
-
-       /* Try to get the request started, abort the request on error */
-       obj_req->state = ACTIVE;
-       if (!start_active_slot(slot)) {
-               obj_req->state = ABORTED;
-               obj_req->slot = NULL;
-               close(obj_req->local); obj_req->local = -1;
-               free(obj_req->url);
-               return;
-       }
-}
-
-static void finish_object_request(struct object_request *obj_req)
-{
-       struct stat st;
-
-       fchmod(obj_req->local, 0444);
-       close(obj_req->local); obj_req->local = -1;
-
-       if (obj_req->http_code == 416) {
-               fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
-       } else if (obj_req->curl_result != CURLE_OK) {
-               if (stat(obj_req->tmpfile, &st) == 0)
-                       if (st.st_size == 0)
-                               unlink(obj_req->tmpfile);
-               return;
-       }
-
-       inflateEnd(&obj_req->stream);
-       SHA1_Final(obj_req->real_sha1, &obj_req->c);
-       if (obj_req->zret != Z_STREAM_END) {
-               unlink(obj_req->tmpfile);
-               return;
-       }
-       if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
-               unlink(obj_req->tmpfile);
-               return;
-       }
-       obj_req->rename =
-               move_temp_to_file(obj_req->tmpfile, obj_req->filename);
-
-       if (obj_req->rename == 0)
-               pull_say("got %s\n", sha1_to_hex(obj_req->sha1));
-}
-
-static void process_object_response(void *callback_data)
-{
-       struct object_request *obj_req =
-               (struct object_request *)callback_data;
-
-       obj_req->curl_result = obj_req->slot->curl_result;
-       obj_req->http_code = obj_req->slot->http_code;
-       obj_req->slot = NULL;
-       obj_req->state = COMPLETE;
-
-       /* Use alternates if necessary */
-       if (missing_target(obj_req)) {
-               fetch_alternates(alt->base);
-               if (obj_req->repo->next != NULL) {
-                       obj_req->repo =
-                               obj_req->repo->next;
-                       close(obj_req->local);
-                       obj_req->local = -1;
-                       start_object_request(obj_req);
-                       return;
-               }
-       }
-
-       finish_object_request(obj_req);
-}
-
-static void release_object_request(struct object_request *obj_req)
-{
-       struct object_request *entry = object_queue_head;
-
-       if (obj_req->local != -1)
-               error("fd leakage in release: %d", obj_req->local);
-       if (obj_req == object_queue_head) {
-               object_queue_head = obj_req->next;
-       } else {
-               while (entry->next != NULL && entry->next != obj_req)
-                       entry = entry->next;
-               if (entry->next == obj_req)
-                       entry->next = entry->next->next;
-       }
-
-       free(obj_req->url);
-       free(obj_req);
-}
-
-#ifdef USE_CURL_MULTI
-static int fill_active_slot(void *unused)
-{
-       struct object_request *obj_req;
-
-       for (obj_req = object_queue_head; obj_req; obj_req = obj_req->next) {
-               if (obj_req->state == WAITING) {
-                       if (has_sha1_file(obj_req->sha1))
-                               obj_req->state = COMPLETE;
-                       else {
-                               start_object_request(obj_req);
-                               return 1;
-                       }
-               }
-       }
-       return 0;
-}
-#endif
-
-void prefetch(unsigned char *sha1)
-{
-       struct object_request *newreq;
-       struct object_request *tail;
-       char *filename = sha1_file_name(sha1);
-
-       newreq = xmalloc(sizeof(*newreq));
-       hashcpy(newreq->sha1, sha1);
-       newreq->repo = alt;
-       newreq->url = NULL;
-       newreq->local = -1;
-       newreq->state = WAITING;
-       snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
-       snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
-                "%s.temp", filename);
-       newreq->slot = NULL;
-       newreq->next = NULL;
-
-       if (object_queue_head == NULL) {
-               object_queue_head = newreq;
-       } else {
-               tail = object_queue_head;
-               while (tail->next != NULL) {
-                       tail = tail->next;
-               }
-               tail->next = newreq;
-       }
-
-#ifdef USE_CURL_MULTI
-       fill_active_slots();
-       step_active_slots();
-#endif
-}
-
-static int fetch_index(struct alt_base *repo, unsigned char *sha1)
-{
-       char *hex = sha1_to_hex(sha1);
-       char *filename;
-       char *url;
-       char tmpfile[PATH_MAX];
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-
-       FILE *indexfile;
-       struct active_request_slot *slot;
-       struct slot_results results;
-
-       if (has_pack_index(sha1))
-               return 0;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting index for pack %s\n", hex);
-
-       url = xmalloc(strlen(repo->base) + 64);
-       sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
-
-       filename = sha1_pack_index_name(sha1);
-       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-       indexfile = fopen(tmpfile, "a");
-       if (!indexfile)
-               return error("Unable to open local file %s for pack index",
-                            filename);
-
-       slot = get_active_slot();
-       slot->results = &results;
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       slot->local = indexfile;
-
-       /* If there is data present from a previous transfer attempt,
-          resume where it left off */
-       prev_posn = ftell(indexfile);
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of index for pack %s at byte %ld\n",
-                               hex, prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
-       }
-
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (results.curl_result != CURLE_OK) {
-                       fclose(indexfile);
-                       return error("Unable to get pack index %s\n%s", url,
-                                    curl_errorstr);
-               }
-       } else {
-               fclose(indexfile);
-               return error("Unable to start request");
-       }
-
-       fclose(indexfile);
-
-       return move_temp_to_file(tmpfile, filename);
-}
-
-static int setup_index(struct alt_base *repo, unsigned char *sha1)
-{
-       struct packed_git *new_pack;
-       if (has_pack_file(sha1))
-               return 0; /* don't list this as something we can get */
-
-       if (fetch_index(repo, sha1))
-               return -1;
-
-       new_pack = parse_pack_index(sha1);
-       new_pack->next = repo->packs;
-       repo->packs = new_pack;
-       return 0;
-}
-
-static void process_alternates_response(void *callback_data)
-{
-       struct alternates_request *alt_req =
-               (struct alternates_request *)callback_data;
-       struct active_request_slot *slot = alt_req->slot;
-       struct alt_base *tail = alt;
-       const char *base = alt_req->base;
-       static const char null_byte = '\0';
-       char *data;
-       int i = 0;
-
-       if (alt_req->http_specific) {
-               if (slot->curl_result != CURLE_OK ||
-                   !alt_req->buffer->posn) {
-
-                       /* Try reusing the slot to get non-http alternates */
-                       alt_req->http_specific = 0;
-                       sprintf(alt_req->url, "%s/objects/info/alternates",
-                               base);
-                       curl_easy_setopt(slot->curl, CURLOPT_URL,
-                                        alt_req->url);
-                       active_requests++;
-                       slot->in_use = 1;
-                       if (slot->finished != NULL)
-                               (*slot->finished) = 0;
-                       if (!start_active_slot(slot)) {
-                               got_alternates = -1;
-                               slot->in_use = 0;
-                               if (slot->finished != NULL)
-                                       (*slot->finished) = 1;
-                       }
-                       return;
-               }
-       } else if (slot->curl_result != CURLE_OK) {
-               if (!missing_target(slot)) {
-                       got_alternates = -1;
-                       return;
-               }
-       }
-
-       fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
-       alt_req->buffer->posn--;
-       data = alt_req->buffer->buffer;
-
-       while (i < alt_req->buffer->posn) {
-               int posn = i;
-               while (posn < alt_req->buffer->posn && data[posn] != '\n')
-                       posn++;
-               if (data[posn] == '\n') {
-                       int okay = 0;
-                       int serverlen = 0;
-                       struct alt_base *newalt;
-                       char *target = NULL;
-                       if (data[i] == '/') {
-                               /* This counts
-                                * http://git.host/pub/scm/linux.git/
-                                * -----------here^
-                                * so memcpy(dst, base, serverlen) will
-                                * copy up to "...git.host".
-                                */
-                               const char *colon_ss = strstr(base,"://");
-                               if (colon_ss) {
-                                       serverlen = (strchr(colon_ss + 3, '/')
-                                                    - base);
-                                       okay = 1;
-                               }
-                       } else if (!memcmp(data + i, "../", 3)) {
-                               /* Relative URL; chop the corresponding
-                                * number of subpath from base (and ../
-                                * from data), and concatenate the result.
-                                *
-                                * The code first drops ../ from data, and
-                                * then drops one ../ from data and one path
-                                * from base.  IOW, one extra ../ is dropped
-                                * from data than path is dropped from base.
-                                *
-                                * This is not wrong.  The alternate in
-                                *     http://git.host/pub/scm/linux.git/
-                                * to borrow from
-                                *     http://git.host/pub/scm/linus.git/
-                                * is ../../linus.git/objects/.  You need
-                                * two ../../ to borrow from your direct
-                                * neighbour.
-                                */
-                               i += 3;
-                               serverlen = strlen(base);
-                               while (i + 2 < posn &&
-                                      !memcmp(data + i, "../", 3)) {
-                                       do {
-                                               serverlen--;
-                                       } while (serverlen &&
-                                                base[serverlen - 1] != '/');
-                                       i += 3;
-                               }
-                               /* If the server got removed, give up. */
-                               okay = strchr(base, ':') - base + 3 <
-                                       serverlen;
-                       } else if (alt_req->http_specific) {
-                               char *colon = strchr(data + i, ':');
-                               char *slash = strchr(data + i, '/');
-                               if (colon && slash && colon < data + posn &&
-                                   slash < data + posn && colon < slash) {
-                                       okay = 1;
-                               }
-                       }
-                       /* skip "objects\n" at end */
-                       if (okay) {
-                               target = xmalloc(serverlen + posn - i - 6);
-                               memcpy(target, base, serverlen);
-                               memcpy(target + serverlen, data + i,
-                                      posn - i - 7);
-                               target[serverlen + posn - i - 7] = 0;
-                               if (get_verbosely)
-                                       fprintf(stderr,
-                                               "Also look at %s\n", target);
-                               newalt = xmalloc(sizeof(*newalt));
-                               newalt->next = NULL;
-                               newalt->base = target;
-                               newalt->got_indices = 0;
-                               newalt->packs = NULL;
-
-                               while (tail->next != NULL)
-                                       tail = tail->next;
-                               tail->next = newalt;
-                       }
-               }
-               i = posn + 1;
-       }
-
-       got_alternates = 1;
-}
-
-static void fetch_alternates(const char *base)
-{
-       struct buffer buffer;
-       char *url;
-       char *data;
-       struct active_request_slot *slot;
-       struct alternates_request alt_req;
-
-       /* If another request has already started fetching alternates,
-          wait for them to arrive and return to processing this request's
-          curl message */
-#ifdef USE_CURL_MULTI
-       while (got_alternates == 0) {
-               step_active_slots();
-       }
-#endif
-
-       /* Nothing to do if they've already been fetched */
-       if (got_alternates == 1)
-               return;
-
-       /* Start the fetch */
-       got_alternates = 0;
-
-       data = xmalloc(4096);
-       buffer.size = 4096;
-       buffer.posn = 0;
-       buffer.buffer = data;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting alternates list for %s\n", base);
-
-       url = xmalloc(strlen(base) + 31);
-       sprintf(url, "%s/objects/info/http-alternates", base);
-
-       /* Use a callback to process the result, since another request
-          may fail and need to have alternates loaded before continuing */
-       slot = get_active_slot();
-       slot->callback_func = process_alternates_response;
-       slot->callback_data = &alt_req;
-
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-
-       alt_req.base = base;
-       alt_req.url = url;
-       alt_req.buffer = &buffer;
-       alt_req.http_specific = 1;
-       alt_req.slot = slot;
-
-       if (start_active_slot(slot))
-               run_active_slot(slot);
-       else
-               got_alternates = -1;
-
-       free(data);
-       free(url);
-}
-
-static int fetch_indices(struct alt_base *repo)
-{
-       unsigned char sha1[20];
-       char *url;
-       struct buffer buffer;
-       char *data;
-       int i = 0;
-
-       struct active_request_slot *slot;
-       struct slot_results results;
-
-       if (repo->got_indices)
-               return 0;
-
-       data = xmalloc(4096);
-       buffer.size = 4096;
-       buffer.posn = 0;
-       buffer.buffer = data;
-
-       if (get_verbosely)
-               fprintf(stderr, "Getting pack list for %s\n", repo->base);
-
-       url = xmalloc(strlen(repo->base) + 21);
-       sprintf(url, "%s/objects/info/packs", repo->base);
-
-       slot = get_active_slot();
-       slot->results = &results;
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (results.curl_result != CURLE_OK) {
-                       if (missing_target(&results)) {
-                               repo->got_indices = 1;
-                               free(buffer.buffer);
-                               return 0;
-                       } else {
-                               repo->got_indices = 0;
-                               free(buffer.buffer);
-                               return error("%s", curl_errorstr);
-                       }
-               }
-       } else {
-               repo->got_indices = 0;
-               free(buffer.buffer);
-               return error("Unable to start request");
-       }
-
-       data = buffer.buffer;
-       while (i < buffer.posn) {
-               switch (data[i]) {
-               case 'P':
-                       i++;
-                       if (i + 52 <= buffer.posn &&
-                           !prefixcmp(data + i, " pack-") &&
-                           !prefixcmp(data + i + 46, ".pack\n")) {
-                               get_sha1_hex(data + i + 6, sha1);
-                               setup_index(repo, sha1);
-                               i += 51;
-                               break;
-                       }
-               default:
-                       while (i < buffer.posn && data[i] != '\n')
-                               i++;
-               }
-               i++;
-       }
-
-       free(buffer.buffer);
-       repo->got_indices = 1;
-       return 0;
-}
-
-static int fetch_pack(struct alt_base *repo, unsigned char *sha1)
-{
-       char *url;
-       struct packed_git *target;
-       struct packed_git **lst;
-       FILE *packfile;
-       char *filename;
-       char tmpfile[PATH_MAX];
-       int ret;
-       long prev_posn = 0;
-       char range[RANGE_HEADER_SIZE];
-       struct curl_slist *range_header = NULL;
-
-       struct active_request_slot *slot;
-       struct slot_results results;
-
-       if (fetch_indices(repo))
-               return -1;
-       target = find_sha1_pack(sha1, repo->packs);
-       if (!target)
-               return -1;
-
-       if (get_verbosely) {
-               fprintf(stderr, "Getting pack %s\n",
-                       sha1_to_hex(target->sha1));
-               fprintf(stderr, " which contains %s\n",
-                       sha1_to_hex(sha1));
-       }
-
-       url = xmalloc(strlen(repo->base) + 65);
-       sprintf(url, "%s/objects/pack/pack-%s.pack",
-               repo->base, sha1_to_hex(target->sha1));
-
-       filename = sha1_pack_name(target->sha1);
-       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
-       packfile = fopen(tmpfile, "a");
-       if (!packfile)
-               return error("Unable to open local file %s for pack",
-                            filename);
-
-       slot = get_active_slot();
-       slot->results = &results;
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);
-       slot->local = packfile;
-
-       /* If there is data present from a previous transfer attempt,
-          resume where it left off */
-       prev_posn = ftell(packfile);
-       if (prev_posn>0) {
-               if (get_verbosely)
-                       fprintf(stderr,
-                               "Resuming fetch of pack %s at byte %ld\n",
-                               sha1_to_hex(target->sha1), prev_posn);
-               sprintf(range, "Range: bytes=%ld-", prev_posn);
-               range_header = curl_slist_append(range_header, range);
-               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
-       }
-
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (results.curl_result != CURLE_OK) {
-                       fclose(packfile);
-                       return error("Unable to get pack file %s\n%s", url,
-                                    curl_errorstr);
-               }
-       } else {
-               fclose(packfile);
-               return error("Unable to start request");
-       }
-
-       target->pack_size = ftell(packfile);
-       fclose(packfile);
-
-       ret = move_temp_to_file(tmpfile, filename);
-       if (ret)
-               return ret;
-
-       lst = &repo->packs;
-       while (*lst != target)
-               lst = &((*lst)->next);
-       *lst = (*lst)->next;
-
-       if (verify_pack(target, 0))
-               return -1;
-       install_packed_git(target);
-
-       return 0;
-}
-
-static void abort_object_request(struct object_request *obj_req)
-{
-       if (obj_req->local >= 0) {
-               close(obj_req->local);
-               obj_req->local = -1;
-       }
-       unlink(obj_req->tmpfile);
-       if (obj_req->slot) {
-               release_active_slot(obj_req->slot);
-               obj_req->slot = NULL;
-       }
-       release_object_request(obj_req);
-}
-
-static int fetch_object(struct alt_base *repo, unsigned char *sha1)
-{
-       char *hex = sha1_to_hex(sha1);
-       int ret = 0;
-       struct object_request *obj_req = object_queue_head;
-
-       while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
-               obj_req = obj_req->next;
-       if (obj_req == NULL)
-               return error("Couldn't find request for %s in the queue", hex);
-
-       if (has_sha1_file(obj_req->sha1)) {
-               abort_object_request(obj_req);
-               return 0;
-       }
-
-#ifdef USE_CURL_MULTI
-       while (obj_req->state == WAITING) {
-               step_active_slots();
-       }
-#else
-       start_object_request(obj_req);
-#endif
-
-       while (obj_req->state == ACTIVE) {
-               run_active_slot(obj_req->slot);
-       }
-       if (obj_req->local != -1) {
-               close(obj_req->local); obj_req->local = -1;
-       }
-
-       if (obj_req->state == ABORTED) {
-               ret = error("Request for %s aborted", hex);
-       } else if (obj_req->curl_result != CURLE_OK &&
-                  obj_req->http_code != 416) {
-               if (missing_target(obj_req))
-                       ret = -1; /* Be silent, it is probably in a pack. */
-               else
-                       ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
-                                   obj_req->errorstr, obj_req->curl_result,
-                                   obj_req->http_code, hex);
-       } else if (obj_req->zret != Z_STREAM_END) {
-               corrupt_object_found++;
-               ret = error("File %s (%s) corrupt", hex, obj_req->url);
-       } else if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
-               ret = error("File %s has bad hash", hex);
-       } else if (obj_req->rename < 0) {
-               ret = error("unable to write sha1 filename %s",
-                           obj_req->filename);
-       }
-
-       release_object_request(obj_req);
-       return ret;
-}
-
-int fetch(unsigned char *sha1)
-{
-       struct alt_base *altbase = alt;
-
-       if (!fetch_object(altbase, sha1))
-               return 0;
-       while (altbase) {
-               if (!fetch_pack(altbase, sha1))
-                       return 0;
-               fetch_alternates(alt->base);
-               altbase = altbase->next;
-       }
-       return error("Unable to find %s under %s", sha1_to_hex(sha1),
-                    alt->base);
-}
-
-static inline int needs_quote(int ch)
-{
-       if (((ch >= 'A') && (ch <= 'Z'))
-                       || ((ch >= 'a') && (ch <= 'z'))
-                       || ((ch >= '0') && (ch <= '9'))
-                       || (ch == '/')
-                       || (ch == '-')
-                       || (ch == '.'))
-               return 0;
-       return 1;
-}
-
-static inline int hex(int v)
-{
-       if (v < 10) return '0' + v;
-       else return 'A' + v - 10;
-}
-
-static char *quote_ref_url(const char *base, const char *ref)
-{
-       const char *cp;
-       char *dp, *qref;
-       int len, baselen, ch;
-
-       baselen = strlen(base);
-       len = baselen + 7; /* "/refs/" + NUL */
-       for (cp = ref; (ch = *cp) != 0; cp++, len++)
-               if (needs_quote(ch))
-                       len += 2; /* extra two hex plus replacement % */
-       qref = xmalloc(len);
-       memcpy(qref, base, baselen);
-       memcpy(qref + baselen, "/refs/", 6);
-       for (cp = ref, dp = qref + baselen + 6; (ch = *cp) != 0; cp++) {
-               if (needs_quote(ch)) {
-                       *dp++ = '%';
-                       *dp++ = hex((ch >> 4) & 0xF);
-                       *dp++ = hex(ch & 0xF);
-               }
-               else
-                       *dp++ = ch;
-       }
-       *dp = 0;
-
-       return qref;
-}
-
-int fetch_ref(char *ref, unsigned char *sha1)
-{
-        char *url;
-        char hex[42];
-        struct buffer buffer;
-       const char *base = alt->base;
-       struct active_request_slot *slot;
-       struct slot_results results;
-        buffer.size = 41;
-        buffer.posn = 0;
-        buffer.buffer = hex;
-        hex[41] = '\0';
-
-       url = quote_ref_url(base, ref);
-       slot = get_active_slot();
-       slot->results = &results;
-       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
-       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
-       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
-       if (start_active_slot(slot)) {
-               run_active_slot(slot);
-               if (results.curl_result != CURLE_OK)
-                       return error("Couldn't get %s for %s\n%s",
-                                    url, ref, curl_errorstr);
-       } else {
-               return error("Unable to start request");
-       }
-
-        hex[40] = '\0';
-        get_sha1_hex(hex, sha1);
-        return 0;
-}
-
-int main(int argc, const char **argv)
-{
-       int commits;
-       const char **write_ref = NULL;
-       char **commit_id;
-       const char *url;
-       char *s;
-       int arg = 1;
-       int rc = 0;
-
-       setup_git_directory();
-       git_config(git_default_config);
-
-       while (arg < argc && argv[arg][0] == '-') {
-               if (argv[arg][1] == 't') {
-                       get_tree = 1;
-               } else if (argv[arg][1] == 'c') {
-                       get_history = 1;
-               } else if (argv[arg][1] == 'a') {
-                       get_all = 1;
-                       get_tree = 1;
-                       get_history = 1;
-               } else if (argv[arg][1] == 'v') {
-                       get_verbosely = 1;
-               } else if (argv[arg][1] == 'w') {
-                       write_ref = &argv[arg + 1];
-                       arg++;
-               } else if (!strcmp(argv[arg], "--recover")) {
-                       get_recover = 1;
-               } else if (!strcmp(argv[arg], "--stdin")) {
-                       commits_on_stdin = 1;
-               }
-               arg++;
-       }
-       if (argc < arg + 2 - commits_on_stdin) {
-               usage("git-http-fetch [-c] [-t] [-a] [-v] [--recover] [-w ref] [--stdin] commit-id url");
-               return 1;
-       }
-       if (commits_on_stdin) {
-               commits = pull_targets_stdin(&commit_id, &write_ref);
-       } else {
-               commit_id = (char **) &argv[arg++];
-               commits = 1;
-       }
-       url = argv[arg];
-
-       http_init();
-
-       no_pragma_header = curl_slist_append(no_pragma_header, "Pragma:");
-
-       alt = xmalloc(sizeof(*alt));
-       alt->base = xmalloc(strlen(url) + 1);
-       strcpy(alt->base, url);
-       for (s = alt->base + strlen(alt->base) - 1; *s == '/'; --s)
-               *s = 0;
-       alt->got_indices = 0;
-       alt->packs = NULL;
-       alt->next = NULL;
-
-#ifdef USE_CURL_MULTI
-       add_fill_function(NULL, fill_active_slot);
-#endif
-
-       if (pull(commits, commit_id, write_ref, url))
-               rc = 1;
-
-       http_cleanup();
-
-       curl_slist_free_all(no_pragma_header);
-
-       if (commits_on_stdin)
-               pull_targets_free(commits, commit_id, write_ref);
-
-       if (corrupt_object_found) {
-               fprintf(stderr,
-"Some loose object were found to be corrupt, but they might be just\n"
-"a false '404 Not Found' error message sent with incorrect HTTP\n"
-"status code.  Suggest running git-fsck.\n");
-       }
-       return rc;
-}

diff --git a/http-push.c b/http-push.c
index c54230b6f3bb873d9d0d3c03d5cfc5ec8cde2177..8e1fdfddf5402add6b6ce787647c522c9a0116ae 100644 (file)
--- a/http-push.c
+++ b/http-push.c
@@ -1,7 +1,6 @@
 #include "cache.h"
 #include "commit.h"
 #include "pack.h"
-#include "fetch.h"
 #include "tag.h"
 #include "blob.h"
 #include "http.h"

diff --git a/http-walker.c b/http-walker.c
new file mode 100644 (file)
index 0000000..444aebf
--- /dev/null
+++ b/http-walker.c
@@ -0,0 +1,1035 @@
+#include "cache.h"
+#include "commit.h"
+#include "pack.h"
+#include "walker.h"
+#include "http.h"
+
+#define PREV_BUF_SIZE 4096
+#define RANGE_HEADER_SIZE 30
+
+struct alt_base
+{
+       char *base;
+       int got_indices;
+       struct packed_git *packs;
+       struct alt_base *next;
+};
+
+enum object_request_state {
+       WAITING,
+       ABORTED,
+       ACTIVE,
+       COMPLETE,
+};
+
+struct object_request
+{
+       struct walker *walker;
+       unsigned char sha1[20];
+       struct alt_base *repo;
+       char *url;
+       char filename[PATH_MAX];
+       char tmpfile[PATH_MAX];
+       int local;
+       enum object_request_state state;
+       CURLcode curl_result;
+       char errorstr[CURL_ERROR_SIZE];
+       long http_code;
+       unsigned char real_sha1[20];
+       SHA_CTX c;
+       z_stream stream;
+       int zret;
+       int rename;
+       struct active_request_slot *slot;
+       struct object_request *next;
+};
+
+struct alternates_request {
+       struct walker *walker;
+       const char *base;
+       char *url;
+       struct buffer *buffer;
+       struct active_request_slot *slot;
+       int http_specific;
+};
+
+struct walker_data {
+       const char *url;
+       int got_alternates;
+       struct alt_base *alt;
+       struct curl_slist *no_pragma_header;
+};
+
+static struct object_request *object_queue_head;
+
+static size_t fwrite_sha1_file(void *ptr, size_t eltsize, size_t nmemb,
+                              void *data)
+{
+       unsigned char expn[4096];
+       size_t size = eltsize * nmemb;
+       int posn = 0;
+       struct object_request *obj_req = (struct object_request *)data;
+       do {
+               ssize_t retval = xwrite(obj_req->local,
+                                      (char *) ptr + posn, size - posn);
+               if (retval < 0)
+                       return posn;
+               posn += retval;
+       } while (posn < size);
+
+       obj_req->stream.avail_in = size;
+       obj_req->stream.next_in = ptr;
+       do {
+               obj_req->stream.next_out = expn;
+               obj_req->stream.avail_out = sizeof(expn);
+               obj_req->zret = inflate(&obj_req->stream, Z_SYNC_FLUSH);
+               SHA1_Update(&obj_req->c, expn,
+                           sizeof(expn) - obj_req->stream.avail_out);
+       } while (obj_req->stream.avail_in && obj_req->zret == Z_OK);
+       data_received++;
+       return size;
+}
+
+static int missing__target(int code, int result)
+{
+       return  /* file:// URL -- do we ever use one??? */
+               (result == CURLE_FILE_COULDNT_READ_FILE) ||
+               /* http:// and https:// URL */
+               (code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
+               /* ftp:// URL */
+               (code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
+               ;
+}
+
+#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
+
+static void fetch_alternates(struct walker *walker, const char *base);
+
+static void process_object_response(void *callback_data);
+
+static void start_object_request(struct walker *walker,
+                                struct object_request *obj_req)
+{
+       char *hex = sha1_to_hex(obj_req->sha1);
+       char prevfile[PATH_MAX];
+       char *url;
+       char *posn;
+       int prevlocal;
+       unsigned char prev_buf[PREV_BUF_SIZE];
+       ssize_t prev_read = 0;
+       long prev_posn = 0;
+       char range[RANGE_HEADER_SIZE];
+       struct curl_slist *range_header = NULL;
+       struct active_request_slot *slot;
+       struct walker_data *data = walker->data;
+
+       snprintf(prevfile, sizeof(prevfile), "%s.prev", obj_req->filename);
+       unlink(prevfile);
+       rename(obj_req->tmpfile, prevfile);
+       unlink(obj_req->tmpfile);
+
+       if (obj_req->local != -1)
+               error("fd leakage in start: %d", obj_req->local);
+       obj_req->local = open(obj_req->tmpfile,
+                             O_WRONLY | O_CREAT | O_EXCL, 0666);
+       /* This could have failed due to the "lazy directory creation";
+        * try to mkdir the last path component.
+        */
+       if (obj_req->local < 0 && errno == ENOENT) {
+               char *dir = strrchr(obj_req->tmpfile, '/');
+               if (dir) {
+                       *dir = 0;
+                       mkdir(obj_req->tmpfile, 0777);
+                       *dir = '/';
+               }
+               obj_req->local = open(obj_req->tmpfile,
+                                     O_WRONLY | O_CREAT | O_EXCL, 0666);
+       }
+
+       if (obj_req->local < 0) {
+               obj_req->state = ABORTED;
+               error("Couldn't create temporary file %s for %s: %s",
+                     obj_req->tmpfile, obj_req->filename, strerror(errno));
+               return;
+       }
+
+       memset(&obj_req->stream, 0, sizeof(obj_req->stream));
+
+       inflateInit(&obj_req->stream);
+
+       SHA1_Init(&obj_req->c);
+
+       url = xmalloc(strlen(obj_req->repo->base) + 51);
+       obj_req->url = xmalloc(strlen(obj_req->repo->base) + 51);
+       strcpy(url, obj_req->repo->base);
+       posn = url + strlen(obj_req->repo->base);
+       strcpy(posn, "/objects/");
+       posn += 9;
+       memcpy(posn, hex, 2);
+       posn += 2;
+       *(posn++) = '/';
+       strcpy(posn, hex + 2);
+       strcpy(obj_req->url, url);
+
+       /* If a previous temp file is present, process what was already
+          fetched. */
+       prevlocal = open(prevfile, O_RDONLY);
+       if (prevlocal != -1) {
+               do {
+                       prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
+                       if (prev_read>0) {
+                               if (fwrite_sha1_file(prev_buf,
+                                                    1,
+                                                    prev_read,
+                                                    obj_req) == prev_read) {
+                                       prev_posn += prev_read;
+                               } else {
+                                       prev_read = -1;
+                               }
+                       }
+               } while (prev_read > 0);
+               close(prevlocal);
+       }
+       unlink(prevfile);
+
+       /* Reset inflate/SHA1 if there was an error reading the previous temp
+          file; also rewind to the beginning of the local file. */
+       if (prev_read == -1) {
+               memset(&obj_req->stream, 0, sizeof(obj_req->stream));
+               inflateInit(&obj_req->stream);
+               SHA1_Init(&obj_req->c);
+               if (prev_posn>0) {
+                       prev_posn = 0;
+                       lseek(obj_req->local, 0, SEEK_SET);
+                       ftruncate(obj_req->local, 0);
+               }
+       }
+
+       slot = get_active_slot();
+       slot->callback_func = process_object_response;
+       slot->callback_data = obj_req;
+       obj_req->slot = slot;
+
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, obj_req);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
+       curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, obj_req->errorstr);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
+
+       /* If we have successfully processed data from a previous fetch
+          attempt, only fetch the data we don't already have. */
+       if (prev_posn>0) {
+               if (walker->get_verbosely)
+                       fprintf(stderr,
+                               "Resuming fetch of object %s at byte %ld\n",
+                               hex, prev_posn);
+               sprintf(range, "Range: bytes=%ld-", prev_posn);
+               range_header = curl_slist_append(range_header, range);
+               curl_easy_setopt(slot->curl,
+                                CURLOPT_HTTPHEADER, range_header);
+       }
+
+       /* Try to get the request started, abort the request on error */
+       obj_req->state = ACTIVE;
+       if (!start_active_slot(slot)) {
+               obj_req->state = ABORTED;
+               obj_req->slot = NULL;
+               close(obj_req->local); obj_req->local = -1;
+               free(obj_req->url);
+               return;
+       }
+}
+
+static void finish_object_request(struct object_request *obj_req)
+{
+       struct stat st;
+
+       fchmod(obj_req->local, 0444);
+       close(obj_req->local); obj_req->local = -1;
+
+       if (obj_req->http_code == 416) {
+               fprintf(stderr, "Warning: requested range invalid; we may already have all the data.\n");
+       } else if (obj_req->curl_result != CURLE_OK) {
+               if (stat(obj_req->tmpfile, &st) == 0)
+                       if (st.st_size == 0)
+                               unlink(obj_req->tmpfile);
+               return;
+       }
+
+       inflateEnd(&obj_req->stream);
+       SHA1_Final(obj_req->real_sha1, &obj_req->c);
+       if (obj_req->zret != Z_STREAM_END) {
+               unlink(obj_req->tmpfile);
+               return;
+       }
+       if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
+               unlink(obj_req->tmpfile);
+               return;
+       }
+       obj_req->rename =
+               move_temp_to_file(obj_req->tmpfile, obj_req->filename);
+
+       if (obj_req->rename == 0)
+               walker_say(obj_req->walker, "got %s\n", sha1_to_hex(obj_req->sha1));
+}
+
+static void process_object_response(void *callback_data)
+{
+       struct object_request *obj_req =
+               (struct object_request *)callback_data;
+       struct walker *walker = obj_req->walker;
+       struct walker_data *data = walker->data;
+       struct alt_base *alt = data->alt;
+
+       obj_req->curl_result = obj_req->slot->curl_result;
+       obj_req->http_code = obj_req->slot->http_code;
+       obj_req->slot = NULL;
+       obj_req->state = COMPLETE;
+
+       /* Use alternates if necessary */
+       if (missing_target(obj_req)) {
+               fetch_alternates(walker, alt->base);
+               if (obj_req->repo->next != NULL) {
+                       obj_req->repo =
+                               obj_req->repo->next;
+                       close(obj_req->local);
+                       obj_req->local = -1;
+                       start_object_request(walker, obj_req);
+                       return;
+               }
+       }
+
+       finish_object_request(obj_req);
+}
+
+static void release_object_request(struct object_request *obj_req)
+{
+       struct object_request *entry = object_queue_head;
+
+       if (obj_req->local != -1)
+               error("fd leakage in release: %d", obj_req->local);
+       if (obj_req == object_queue_head) {
+               object_queue_head = obj_req->next;
+       } else {
+               while (entry->next != NULL && entry->next != obj_req)
+                       entry = entry->next;
+               if (entry->next == obj_req)
+                       entry->next = entry->next->next;
+       }
+
+       free(obj_req->url);
+       free(obj_req);
+}
+
+#ifdef USE_CURL_MULTI
+static int fill_active_slot(struct walker *walker)
+{
+       struct object_request *obj_req;
+
+       for (obj_req = object_queue_head; obj_req; obj_req = obj_req->next) {
+               if (obj_req->state == WAITING) {
+                       if (has_sha1_file(obj_req->sha1))
+                               obj_req->state = COMPLETE;
+                       else {
+                               start_object_request(walker, obj_req);
+                               return 1;
+                       }
+               }
+       }
+       return 0;
+}
+#endif
+
+static void prefetch(struct walker *walker, unsigned char *sha1)
+{
+       struct object_request *newreq;
+       struct object_request *tail;
+       struct walker_data *data = walker->data;
+       char *filename = sha1_file_name(sha1);
+
+       newreq = xmalloc(sizeof(*newreq));
+       newreq->walker = walker;
+       hashcpy(newreq->sha1, sha1);
+       newreq->repo = data->alt;
+       newreq->url = NULL;
+       newreq->local = -1;
+       newreq->state = WAITING;
+       snprintf(newreq->filename, sizeof(newreq->filename), "%s", filename);
+       snprintf(newreq->tmpfile, sizeof(newreq->tmpfile),
+                "%s.temp", filename);
+       newreq->slot = NULL;
+       newreq->next = NULL;
+
+       if (object_queue_head == NULL) {
+               object_queue_head = newreq;
+       } else {
+               tail = object_queue_head;
+               while (tail->next != NULL) {
+                       tail = tail->next;
+               }
+               tail->next = newreq;
+       }
+
+#ifdef USE_CURL_MULTI
+       fill_active_slots();
+       step_active_slots();
+#endif
+}
+
+static int fetch_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
+{
+       char *hex = sha1_to_hex(sha1);
+       char *filename;
+       char *url;
+       char tmpfile[PATH_MAX];
+       long prev_posn = 0;
+       char range[RANGE_HEADER_SIZE];
+       struct curl_slist *range_header = NULL;
+       struct walker_data *data = walker->data;
+
+       FILE *indexfile;
+       struct active_request_slot *slot;
+       struct slot_results results;
+
+       if (has_pack_index(sha1))
+               return 0;
+
+       if (walker->get_verbosely)
+               fprintf(stderr, "Getting index for pack %s\n", hex);
+
+       url = xmalloc(strlen(repo->base) + 64);
+       sprintf(url, "%s/objects/pack/pack-%s.idx", repo->base, hex);
+
+       filename = sha1_pack_index_name(sha1);
+       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
+       indexfile = fopen(tmpfile, "a");
+       if (!indexfile)
+               return error("Unable to open local file %s for pack index",
+                            filename);
+
+       slot = get_active_slot();
+       slot->results = &results;
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, indexfile);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
+       slot->local = indexfile;
+
+       /* If there is data present from a previous transfer attempt,
+          resume where it left off */
+       prev_posn = ftell(indexfile);
+       if (prev_posn>0) {
+               if (walker->get_verbosely)
+                       fprintf(stderr,
+                               "Resuming fetch of index for pack %s at byte %ld\n",
+                               hex, prev_posn);
+               sprintf(range, "Range: bytes=%ld-", prev_posn);
+               range_header = curl_slist_append(range_header, range);
+               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
+       }
+
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK) {
+                       fclose(indexfile);
+                       return error("Unable to get pack index %s\n%s", url,
+                                    curl_errorstr);
+               }
+       } else {
+               fclose(indexfile);
+               return error("Unable to start request");
+       }
+
+       fclose(indexfile);
+
+       return move_temp_to_file(tmpfile, filename);
+}
+
+static int setup_index(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
+{
+       struct packed_git *new_pack;
+       if (has_pack_file(sha1))
+               return 0; /* don't list this as something we can get */
+
+       if (fetch_index(walker, repo, sha1))
+               return -1;
+
+       new_pack = parse_pack_index(sha1);
+       new_pack->next = repo->packs;
+       repo->packs = new_pack;
+       return 0;
+}
+
+static void process_alternates_response(void *callback_data)
+{
+       struct alternates_request *alt_req =
+               (struct alternates_request *)callback_data;
+       struct walker *walker = alt_req->walker;
+       struct walker_data *cdata = walker->data;
+       struct active_request_slot *slot = alt_req->slot;
+       struct alt_base *tail = cdata->alt;
+       const char *base = alt_req->base;
+       static const char null_byte = '\0';
+       char *data;
+       int i = 0;
+
+       if (alt_req->http_specific) {
+               if (slot->curl_result != CURLE_OK ||
+                   !alt_req->buffer->posn) {
+
+                       /* Try reusing the slot to get non-http alternates */
+                       alt_req->http_specific = 0;
+                       sprintf(alt_req->url, "%s/objects/info/alternates",
+                               base);
+                       curl_easy_setopt(slot->curl, CURLOPT_URL,
+                                        alt_req->url);
+                       active_requests++;
+                       slot->in_use = 1;
+                       if (slot->finished != NULL)
+                               (*slot->finished) = 0;
+                       if (!start_active_slot(slot)) {
+                               cdata->got_alternates = -1;
+                               slot->in_use = 0;
+                               if (slot->finished != NULL)
+                                       (*slot->finished) = 1;
+                       }
+                       return;
+               }
+       } else if (slot->curl_result != CURLE_OK) {
+               if (!missing_target(slot)) {
+                       cdata->got_alternates = -1;
+                       return;
+               }
+       }
+
+       fwrite_buffer(&null_byte, 1, 1, alt_req->buffer);
+       alt_req->buffer->posn--;
+       data = alt_req->buffer->buffer;
+
+       while (i < alt_req->buffer->posn) {
+               int posn = i;
+               while (posn < alt_req->buffer->posn && data[posn] != '\n')
+                       posn++;
+               if (data[posn] == '\n') {
+                       int okay = 0;
+                       int serverlen = 0;
+                       struct alt_base *newalt;
+                       char *target = NULL;
+                       if (data[i] == '/') {
+                               /* This counts
+                                * http://git.host/pub/scm/linux.git/
+                                * -----------here^
+                                * so memcpy(dst, base, serverlen) will
+                                * copy up to "...git.host".
+                                */
+                               const char *colon_ss = strstr(base,"://");
+                               if (colon_ss) {
+                                       serverlen = (strchr(colon_ss + 3, '/')
+                                                    - base);
+                                       okay = 1;
+                               }
+                       } else if (!memcmp(data + i, "../", 3)) {
+                               /* Relative URL; chop the corresponding
+                                * number of subpath from base (and ../
+                                * from data), and concatenate the result.
+                                *
+                                * The code first drops ../ from data, and
+                                * then drops one ../ from data and one path
+                                * from base.  IOW, one extra ../ is dropped
+                                * from data than path is dropped from base.
+                                *
+                                * This is not wrong.  The alternate in
+                                *     http://git.host/pub/scm/linux.git/
+                                * to borrow from
+                                *     http://git.host/pub/scm/linus.git/
+                                * is ../../linus.git/objects/.  You need
+                                * two ../../ to borrow from your direct
+                                * neighbour.
+                                */
+                               i += 3;
+                               serverlen = strlen(base);
+                               while (i + 2 < posn &&
+                                      !memcmp(data + i, "../", 3)) {
+                                       do {
+                                               serverlen--;
+                                       } while (serverlen &&
+                                                base[serverlen - 1] != '/');
+                                       i += 3;
+                               }
+                               /* If the server got removed, give up. */
+                               okay = strchr(base, ':') - base + 3 <
+                                       serverlen;
+                       } else if (alt_req->http_specific) {
+                               char *colon = strchr(data + i, ':');
+                               char *slash = strchr(data + i, '/');
+                               if (colon && slash && colon < data + posn &&
+                                   slash < data + posn && colon < slash) {
+                                       okay = 1;
+                               }
+                       }
+                       /* skip "objects\n" at end */
+                       if (okay) {
+                               target = xmalloc(serverlen + posn - i - 6);
+                               memcpy(target, base, serverlen);
+                               memcpy(target + serverlen, data + i,
+                                      posn - i - 7);
+                               target[serverlen + posn - i - 7] = 0;
+                               if (walker->get_verbosely)
+                                       fprintf(stderr,
+                                               "Also look at %s\n", target);
+                               newalt = xmalloc(sizeof(*newalt));
+                               newalt->next = NULL;
+                               newalt->base = target;
+                               newalt->got_indices = 0;
+                               newalt->packs = NULL;
+
+                               while (tail->next != NULL)
+                                       tail = tail->next;
+                               tail->next = newalt;
+                       }
+               }
+               i = posn + 1;
+       }
+
+       cdata->got_alternates = 1;
+}
+
+static void fetch_alternates(struct walker *walker, const char *base)
+{
+       struct buffer buffer;
+       char *url;
+       char *data;
+       struct active_request_slot *slot;
+       struct alternates_request alt_req;
+       struct walker_data *cdata = walker->data;
+
+       /* If another request has already started fetching alternates,
+          wait for them to arrive and return to processing this request's
+          curl message */
+#ifdef USE_CURL_MULTI
+       while (cdata->got_alternates == 0) {
+               step_active_slots();
+       }
+#endif
+
+       /* Nothing to do if they've already been fetched */
+       if (cdata->got_alternates == 1)
+               return;
+
+       /* Start the fetch */
+       cdata->got_alternates = 0;
+
+       data = xmalloc(4096);
+       buffer.size = 4096;
+       buffer.posn = 0;
+       buffer.buffer = data;
+
+       if (walker->get_verbosely)
+               fprintf(stderr, "Getting alternates list for %s\n", base);
+
+       url = xmalloc(strlen(base) + 31);
+       sprintf(url, "%s/objects/info/http-alternates", base);
+
+       /* Use a callback to process the result, since another request
+          may fail and need to have alternates loaded before continuing */
+       slot = get_active_slot();
+       slot->callback_func = process_alternates_response;
+       alt_req.walker = walker;
+       slot->callback_data = &alt_req;
+
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+
+       alt_req.base = base;
+       alt_req.url = url;
+       alt_req.buffer = &buffer;
+       alt_req.http_specific = 1;
+       alt_req.slot = slot;
+
+       if (start_active_slot(slot))
+               run_active_slot(slot);
+       else
+               cdata->got_alternates = -1;
+
+       free(data);
+       free(url);
+}
+
+static int fetch_indices(struct walker *walker, struct alt_base *repo)
+{
+       unsigned char sha1[20];
+       char *url;
+       struct buffer buffer;
+       char *data;
+       int i = 0;
+
+       struct active_request_slot *slot;
+       struct slot_results results;
+
+       if (repo->got_indices)
+               return 0;
+
+       data = xmalloc(4096);
+       buffer.size = 4096;
+       buffer.posn = 0;
+       buffer.buffer = data;
+
+       if (walker->get_verbosely)
+               fprintf(stderr, "Getting pack list for %s\n", repo->base);
+
+       url = xmalloc(strlen(repo->base) + 21);
+       sprintf(url, "%s/objects/info/packs", repo->base);
+
+       slot = get_active_slot();
+       slot->results = &results;
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK) {
+                       if (missing_target(&results)) {
+                               repo->got_indices = 1;
+                               free(buffer.buffer);
+                               return 0;
+                       } else {
+                               repo->got_indices = 0;
+                               free(buffer.buffer);
+                               return error("%s", curl_errorstr);
+                       }
+               }
+       } else {
+               repo->got_indices = 0;
+               free(buffer.buffer);
+               return error("Unable to start request");
+       }
+
+       data = buffer.buffer;
+       while (i < buffer.posn) {
+               switch (data[i]) {
+               case 'P':
+                       i++;
+                       if (i + 52 <= buffer.posn &&
+                           !prefixcmp(data + i, " pack-") &&
+                           !prefixcmp(data + i + 46, ".pack\n")) {
+                               get_sha1_hex(data + i + 6, sha1);
+                               setup_index(walker, repo, sha1);
+                               i += 51;
+                               break;
+                       }
+               default:
+                       while (i < buffer.posn && data[i] != '\n')
+                               i++;
+               }
+               i++;
+       }
+
+       free(buffer.buffer);
+       repo->got_indices = 1;
+       return 0;
+}
+
+static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
+{
+       char *url;
+       struct packed_git *target;
+       struct packed_git **lst;
+       FILE *packfile;
+       char *filename;
+       char tmpfile[PATH_MAX];
+       int ret;
+       long prev_posn = 0;
+       char range[RANGE_HEADER_SIZE];
+       struct curl_slist *range_header = NULL;
+       struct walker_data *data = walker->data;
+
+       struct active_request_slot *slot;
+       struct slot_results results;
+
+       if (fetch_indices(walker, repo))
+               return -1;
+       target = find_sha1_pack(sha1, repo->packs);
+       if (!target)
+               return -1;
+
+       if (walker->get_verbosely) {
+               fprintf(stderr, "Getting pack %s\n",
+                       sha1_to_hex(target->sha1));
+               fprintf(stderr, " which contains %s\n",
+                       sha1_to_hex(sha1));
+       }
+
+       url = xmalloc(strlen(repo->base) + 65);
+       sprintf(url, "%s/objects/pack/pack-%s.pack",
+               repo->base, sha1_to_hex(target->sha1));
+
+       filename = sha1_pack_name(target->sha1);
+       snprintf(tmpfile, sizeof(tmpfile), "%s.temp", filename);
+       packfile = fopen(tmpfile, "a");
+       if (!packfile)
+               return error("Unable to open local file %s for pack",
+                            filename);
+
+       slot = get_active_slot();
+       slot->results = &results;
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, packfile);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, data->no_pragma_header);
+       slot->local = packfile;
+
+       /* If there is data present from a previous transfer attempt,
+          resume where it left off */
+       prev_posn = ftell(packfile);
+       if (prev_posn>0) {
+               if (walker->get_verbosely)
+                       fprintf(stderr,
+                               "Resuming fetch of pack %s at byte %ld\n",
+                               sha1_to_hex(target->sha1), prev_posn);
+               sprintf(range, "Range: bytes=%ld-", prev_posn);
+               range_header = curl_slist_append(range_header, range);
+               curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, range_header);
+       }
+
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK) {
+                       fclose(packfile);
+                       return error("Unable to get pack file %s\n%s", url,
+                                    curl_errorstr);
+               }
+       } else {
+               fclose(packfile);
+               return error("Unable to start request");
+       }
+
+       target->pack_size = ftell(packfile);
+       fclose(packfile);
+
+       ret = move_temp_to_file(tmpfile, filename);
+       if (ret)
+               return ret;
+
+       lst = &repo->packs;
+       while (*lst != target)
+               lst = &((*lst)->next);
+       *lst = (*lst)->next;
+
+       if (verify_pack(target, 0))
+               return -1;
+       install_packed_git(target);
+
+       return 0;
+}
+
+static void abort_object_request(struct object_request *obj_req)
+{
+       if (obj_req->local >= 0) {
+               close(obj_req->local);
+               obj_req->local = -1;
+       }
+       unlink(obj_req->tmpfile);
+       if (obj_req->slot) {
+               release_active_slot(obj_req->slot);
+               obj_req->slot = NULL;
+       }
+       release_object_request(obj_req);
+}
+
+static int fetch_object(struct walker *walker, struct alt_base *repo, unsigned char *sha1)
+{
+       char *hex = sha1_to_hex(sha1);
+       int ret = 0;
+       struct object_request *obj_req = object_queue_head;
+
+       while (obj_req != NULL && hashcmp(obj_req->sha1, sha1))
+               obj_req = obj_req->next;
+       if (obj_req == NULL)
+               return error("Couldn't find request for %s in the queue", hex);
+
+       if (has_sha1_file(obj_req->sha1)) {
+               abort_object_request(obj_req);
+               return 0;
+       }
+
+#ifdef USE_CURL_MULTI
+       while (obj_req->state == WAITING) {
+               step_active_slots();
+       }
+#else
+       start_object_request(walker, obj_req);
+#endif
+
+       while (obj_req->state == ACTIVE) {
+               run_active_slot(obj_req->slot);
+       }
+       if (obj_req->local != -1) {
+               close(obj_req->local); obj_req->local = -1;
+       }
+
+       if (obj_req->state == ABORTED) {
+               ret = error("Request for %s aborted", hex);
+       } else if (obj_req->curl_result != CURLE_OK &&
+                  obj_req->http_code != 416) {
+               if (missing_target(obj_req))
+                       ret = -1; /* Be silent, it is probably in a pack. */
+               else
+                       ret = error("%s (curl_result = %d, http_code = %ld, sha1 = %s)",
+                                   obj_req->errorstr, obj_req->curl_result,
+                                   obj_req->http_code, hex);
+       } else if (obj_req->zret != Z_STREAM_END) {
+               walker->corrupt_object_found++;
+               ret = error("File %s (%s) corrupt", hex, obj_req->url);
+       } else if (hashcmp(obj_req->sha1, obj_req->real_sha1)) {
+               ret = error("File %s has bad hash", hex);
+       } else if (obj_req->rename < 0) {
+               ret = error("unable to write sha1 filename %s",
+                           obj_req->filename);
+       }
+
+       release_object_request(obj_req);
+       return ret;
+}
+
+static int fetch(struct walker *walker, unsigned char *sha1)
+{
+       struct walker_data *data = walker->data;
+       struct alt_base *altbase = data->alt;
+
+       if (!fetch_object(walker, altbase, sha1))
+               return 0;
+       while (altbase) {
+               if (!fetch_pack(walker, altbase, sha1))
+                       return 0;
+               fetch_alternates(walker, data->alt->base);
+               altbase = altbase->next;
+       }
+       return error("Unable to find %s under %s", sha1_to_hex(sha1),
+                    data->alt->base);
+}
+
+static inline int needs_quote(int ch)
+{
+       if (((ch >= 'A') && (ch <= 'Z'))
+                       || ((ch >= 'a') && (ch <= 'z'))
+                       || ((ch >= '0') && (ch <= '9'))
+                       || (ch == '/')
+                       || (ch == '-')
+                       || (ch == '.'))
+               return 0;
+       return 1;
+}
+
+static inline int hex(int v)
+{
+       if (v < 10) return '0' + v;
+       else return 'A' + v - 10;
+}
+
+static char *quote_ref_url(const char *base, const char *ref)
+{
+       const char *cp;
+       char *dp, *qref;
+       int len, baselen, ch;
+
+       baselen = strlen(base);
+       len = baselen + 7; /* "/refs/" + NUL */
+       for (cp = ref; (ch = *cp) != 0; cp++, len++)
+               if (needs_quote(ch))
+                       len += 2; /* extra two hex plus replacement % */
+       qref = xmalloc(len);
+       memcpy(qref, base, baselen);
+       memcpy(qref + baselen, "/refs/", 6);
+       for (cp = ref, dp = qref + baselen + 6; (ch = *cp) != 0; cp++) {
+               if (needs_quote(ch)) {
+                       *dp++ = '%';
+                       *dp++ = hex((ch >> 4) & 0xF);
+                       *dp++ = hex(ch & 0xF);
+               }
+               else
+                       *dp++ = ch;
+       }
+       *dp = 0;
+
+       return qref;
+}
+
+static int fetch_ref(struct walker *walker, char *ref, unsigned char *sha1)
+{
+        char *url;
+        char hex[42];
+        struct buffer buffer;
+       struct walker_data *data = walker->data;
+       const char *base = data->alt->base;
+       struct active_request_slot *slot;
+       struct slot_results results;
+        buffer.size = 41;
+        buffer.posn = 0;
+        buffer.buffer = hex;
+        hex[41] = '\0';
+
+       url = quote_ref_url(base, ref);
+       slot = get_active_slot();
+       slot->results = &results;
+       curl_easy_setopt(slot->curl, CURLOPT_FILE, &buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+       curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, NULL);
+       curl_easy_setopt(slot->curl, CURLOPT_URL, url);
+       if (start_active_slot(slot)) {
+               run_active_slot(slot);
+               if (results.curl_result != CURLE_OK)
+                       return error("Couldn't get %s for %s\n%s",
+                                    url, ref, curl_errorstr);
+       } else {
+               return error("Unable to start request");
+       }
+
+        hex[40] = '\0';
+        get_sha1_hex(hex, sha1);
+        return 0;
+}
+
+static void cleanup(struct walker *walker)
+{
+       struct walker_data *data = walker->data;
+       http_cleanup();
+
+       curl_slist_free_all(data->no_pragma_header);
+}
+
+struct walker *get_http_walker(const char *url)
+{
+       char *s;
+       struct walker_data *data = xmalloc(sizeof(struct walker_data));
+       struct walker *walker = xmalloc(sizeof(struct walker));
+
+       http_init();
+
+       data->no_pragma_header = curl_slist_append(NULL, "Pragma:");
+
+       data->alt = xmalloc(sizeof(*data->alt));
+       data->alt->base = xmalloc(strlen(url) + 1);
+       strcpy(data->alt->base, url);
+       for (s = data->alt->base + strlen(data->alt->base) - 1; *s == '/'; --s)
+               *s = 0;
+
+       data->alt->got_indices = 0;
+       data->alt->packs = NULL;
+       data->alt->next = NULL;
+       data->got_alternates = -1;
+
+       walker->corrupt_object_found = 0;
+       walker->fetch = fetch;
+       walker->fetch_ref = fetch_ref;
+       walker->prefetch = prefetch;
+       walker->cleanup = cleanup;
+       walker->data = data;
+
+#ifdef USE_CURL_MULTI
+       add_fill_function(walker, (int (*)(void *)) fill_active_slot);
+#endif
+
+       return walker;
+}

diff --git a/walker.c b/walker.c
new file mode 100644 (file)
index 0000000..5c65ea4
--- /dev/null
+++ b/walker.c
@@ -0,0 +1,318 @@
+#include "cache.h"
+#include "walker.h"
+#include "commit.h"
+#include "tree.h"
+#include "tree-walk.h"
+#include "tag.h"
+#include "blob.h"
+#include "refs.h"
+#include "strbuf.h"
+
+static unsigned char current_commit_sha1[20];
+
+void walker_say(struct walker *walker, const char *fmt, const char *hex)
+{
+       if (walker->get_verbosely)
+               fprintf(stderr, fmt, hex);
+}
+
+static void report_missing(const struct object *obj)
+{
+       char missing_hex[41];
+       strcpy(missing_hex, sha1_to_hex(obj->sha1));;
+       fprintf(stderr, "Cannot obtain needed %s %s\n",
+               obj->type ? typename(obj->type): "object", missing_hex);
+       if (!is_null_sha1(current_commit_sha1))
+               fprintf(stderr, "while processing commit %s.\n",
+                       sha1_to_hex(current_commit_sha1));
+}
+
+static int process(struct walker *walker, struct object *obj);
+
+static int process_tree(struct walker *walker, struct tree *tree)
+{
+       struct tree_desc desc;
+       struct name_entry entry;
+
+       if (parse_tree(tree))
+               return -1;
+
+       init_tree_desc(&desc, tree->buffer, tree->size);
+       while (tree_entry(&desc, &entry)) {
+               struct object *obj = NULL;
+
+               /* submodule commits are not stored in the superproject */
+               if (S_ISGITLINK(entry.mode))
+                       continue;
+               if (S_ISDIR(entry.mode)) {
+                       struct tree *tree = lookup_tree(entry.sha1);
+                       if (tree)
+                               obj = &tree->object;
+               }
+               else {
+                       struct blob *blob = lookup_blob(entry.sha1);
+                       if (blob)
+                               obj = &blob->object;
+               }
+               if (!obj || process(walker, obj))
+                       return -1;
+       }
+       free(tree->buffer);
+       tree->buffer = NULL;
+       tree->size = 0;
+       return 0;
+}
+
+#define COMPLETE       (1U << 0)
+#define SEEN           (1U << 1)
+#define TO_SCAN                (1U << 2)
+
+static struct commit_list *complete = NULL;
+
+static int process_commit(struct walker *walker, struct commit *commit)
+{
+       if (parse_commit(commit))
+               return -1;
+
+       while (complete && complete->item->date >= commit->date) {
+               pop_most_recent_commit(&complete, COMPLETE);
+       }
+
+       if (commit->object.flags & COMPLETE)
+               return 0;
+
+       hashcpy(current_commit_sha1, commit->object.sha1);
+
+       walker_say(walker, "walk %s\n", sha1_to_hex(commit->object.sha1));
+
+       if (walker->get_tree) {
+               if (process(walker, &commit->tree->object))
+                       return -1;
+               if (!walker->get_all)
+                       walker->get_tree = 0;
+       }
+       if (walker->get_history) {
+               struct commit_list *parents = commit->parents;
+               for (; parents; parents = parents->next) {
+                       if (process(walker, &parents->item->object))
+                               return -1;
+               }
+       }
+       return 0;
+}
+
+static int process_tag(struct walker *walker, struct tag *tag)
+{
+       if (parse_tag(tag))
+               return -1;
+       return process(walker, tag->tagged);
+}
+
+static struct object_list *process_queue = NULL;
+static struct object_list **process_queue_end = &process_queue;
+
+static int process_object(struct walker *walker, struct object *obj)
+{
+       if (obj->type == OBJ_COMMIT) {
+               if (process_commit(walker, (struct commit *)obj))
+                       return -1;
+               return 0;
+       }
+       if (obj->type == OBJ_TREE) {
+               if (process_tree(walker, (struct tree *)obj))
+                       return -1;
+               return 0;
+       }
+       if (obj->type == OBJ_BLOB) {
+               return 0;
+       }
+       if (obj->type == OBJ_TAG) {
+               if (process_tag(walker, (struct tag *)obj))
+                       return -1;
+               return 0;
+       }
+       return error("Unable to determine requirements "
+                    "of type %s for %s",
+                    typename(obj->type), sha1_to_hex(obj->sha1));
+}
+
+static int process(struct walker *walker, struct object *obj)
+{
+       if (obj->flags & SEEN)
+               return 0;
+       obj->flags |= SEEN;
+
+       if (has_sha1_file(obj->sha1)) {
+               /* We already have it, so we should scan it now. */
+               obj->flags |= TO_SCAN;
+       }
+       else {
+               if (obj->flags & COMPLETE)
+                       return 0;
+               walker->prefetch(walker, obj->sha1);
+       }
+
+       object_list_insert(obj, process_queue_end);
+       process_queue_end = &(*process_queue_end)->next;
+       return 0;
+}
+
+static int loop(struct walker *walker)
+{
+       struct object_list *elem;
+
+       while (process_queue) {
+               struct object *obj = process_queue->item;
+               elem = process_queue;
+               process_queue = elem->next;
+               free(elem);
+               if (!process_queue)
+                       process_queue_end = &process_queue;
+
+               /* If we are not scanning this object, we placed it in
+                * the queue because we needed to fetch it first.
+                */
+               if (! (obj->flags & TO_SCAN)) {
+                       if (walker->fetch(walker, obj->sha1)) {
+                               report_missing(obj);
+                               return -1;
+                       }
+               }
+               if (!obj->type)
+                       parse_object(obj->sha1);
+               if (process_object(walker, obj))
+                       return -1;
+       }
+       return 0;
+}
+
+static int interpret_target(struct walker *walker, char *target, unsigned char *sha1)
+{
+       if (!get_sha1_hex(target, sha1))
+               return 0;
+       if (!check_ref_format(target)) {
+               if (!walker->fetch_ref(walker, target, sha1)) {
+                       return 0;
+               }
+       }
+       return -1;
+}
+
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+       struct commit *commit = lookup_commit_reference_gently(sha1, 1);
+       if (commit) {
+               commit->object.flags |= COMPLETE;
+               insert_by_date(commit, &complete);
+       }
+       return 0;
+}
+
+int walker_targets_stdin(char ***target, const char ***write_ref)
+{
+       int targets = 0, targets_alloc = 0;
+       struct strbuf buf;
+       *target = NULL; *write_ref = NULL;
+       strbuf_init(&buf);
+       while (1) {
+               char *rf_one = NULL;
+               char *tg_one;
+
+               read_line(&buf, stdin, '\n');
+               if (buf.eof)
+                       break;
+               tg_one = buf.buf;
+               rf_one = strchr(tg_one, '\t');
+               if (rf_one)
+                       *rf_one++ = 0;
+
+               if (targets >= targets_alloc) {
+                       targets_alloc = targets_alloc ? targets_alloc * 2 : 64;
+                       *target = xrealloc(*target, targets_alloc * sizeof(**target));
+                       *write_ref = xrealloc(*write_ref, targets_alloc * sizeof(**write_ref));
+               }
+               (*target)[targets] = xstrdup(tg_one);
+               (*write_ref)[targets] = rf_one ? xstrdup(rf_one) : NULL;
+               targets++;
+       }
+       return targets;
+}
+
+void walker_targets_free(int targets, char **target, const char **write_ref)
+{
+       while (targets--) {
+               free(target[targets]);
+               if (write_ref && write_ref[targets])
+                       free((char *) write_ref[targets]);
+       }
+}
+
+int walker_fetch(struct walker *walker, int targets, char **target,
+                const char **write_ref, const char *write_ref_log_details)
+{
+       struct ref_lock **lock = xcalloc(targets, sizeof(struct ref_lock *));
+       unsigned char *sha1 = xmalloc(targets * 20);
+       char *msg;
+       int ret;
+       int i;
+
+       save_commit_buffer = 0;
+       track_object_refs = 0;
+
+       for (i = 0; i < targets; i++) {
+               if (!write_ref || !write_ref[i])
+                       continue;
+
+               lock[i] = lock_ref_sha1(write_ref[i], NULL);
+               if (!lock[i]) {
+                       error("Can't lock ref %s", write_ref[i]);
+                       goto unlock_and_fail;
+               }
+       }
+
+       if (!walker->get_recover)
+               for_each_ref(mark_complete, NULL);
+
+       for (i = 0; i < targets; i++) {
+               if (interpret_target(walker, target[i], &sha1[20 * i])) {
+                       error("Could not interpret %s as something to pull", target[i]);
+                       goto unlock_and_fail;
+               }
+               if (process(walker, lookup_unknown_object(&sha1[20 * i])))
+                       goto unlock_and_fail;
+       }
+
+       if (loop(walker))
+               goto unlock_and_fail;
+
+       if (write_ref_log_details) {
+               msg = xmalloc(strlen(write_ref_log_details) + 12);
+               sprintf(msg, "fetch from %s", write_ref_log_details);
+       } else {
+               msg = NULL;
+       }
+       for (i = 0; i < targets; i++) {
+               if (!write_ref || !write_ref[i])
+                       continue;
+               ret = write_ref_sha1(lock[i], &sha1[20 * i], msg ? msg : "fetch (unknown)");
+               lock[i] = NULL;
+               if (ret)
+                       goto unlock_and_fail;
+       }
+       free(msg);
+
+       return 0;
+
+unlock_and_fail:
+       for (i = 0; i < targets; i++)
+               if (lock[i])
+                       unlock_ref(lock[i]);
+
+       return -1;
+}
+
+void walker_free(struct walker *walker)
+{
+       walker->cleanup(walker);
+       free(walker);
+}

diff --git a/walker.h b/walker.h
new file mode 100644 (file)
index 0000000..ea2c363
--- /dev/null
+++ b/walker.h
@@ -0,0 +1,37 @@
+#ifndef WALKER_H
+#define WALKER_H
+
+struct walker {
+       void *data;
+       int (*fetch_ref)(struct walker *, char *ref, unsigned char *sha1);
+       void (*prefetch)(struct walker *, unsigned char *sha1);
+       int (*fetch)(struct walker *, unsigned char *sha1);
+       void (*cleanup)(struct walker *);
+       int get_tree;
+       int get_history;
+       int get_all;
+       int get_verbosely;
+       int get_recover;
+
+       int corrupt_object_found;
+};
+
+/* Report what we got under get_verbosely */
+void walker_say(struct walker *walker, const char *, const char *);
+
+/* Load pull targets from stdin */
+int walker_targets_stdin(char ***target, const char ***write_ref);
+
+/* Free up loaded targets */
+void walker_targets_free(int targets, char **target, const char **write_ref);
+
+/* If write_ref is set, the ref filename to write the target value to. */
+/* If write_ref_log_details is set, additional text will appear in the ref log. */
+int walker_fetch(struct walker *impl, int targets, char **target,
+                const char **write_ref, const char *write_ref_log_details);
+
+void walker_free(struct walker *walker);
+
+struct walker *get_http_walker(const char *url);
+
+#endif /* WALKER_H */