[PATCH] Implementations of parsing functions

This implements the parsing functions.

Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/blob.c b/blob.c
new file mode 100644 (file)
index 0000000..35031af
--- /dev/null
+++ b/blob.c
@@ -0,0 +1,24 @@
+#include "blob.h"
+#include "cache.h"
+#include <stdlib.h>
+
+const char *blob_type = "blob";
+
+struct blob *lookup_blob(unsigned char *sha1)
+{
+       struct object *obj = lookup_object(sha1);
+       if (!obj) {
+               struct blob *ret = malloc(sizeof(struct blob));
+               memset(ret, 0, sizeof(struct blob));
+               created_object(sha1, &ret->object);
+               ret->object.type = blob_type;
+               ret->object.parsed = 1;
+               return ret;
+       }
+       if (obj->parsed && obj->type != blob_type) {
+               error("Object %s is a %s, not a blob", 
+                     sha1_to_hex(sha1), obj->type);
+               return NULL;
+       }
+       return (struct blob *) obj;
+}

diff --git a/commit.c b/commit.c
new file mode 100644 (file)
index 0000000..eda45d7
--- /dev/null
+++ b/commit.c
@@ -0,0 +1,85 @@
+#include "commit.h"
+#include "cache.h"
+#include <string.h>
+
+const char *commit_type = "commit";
+
+struct commit *lookup_commit(unsigned char *sha1)
+{
+       struct object *obj = lookup_object(sha1);
+       if (!obj) {
+               struct commit *ret = malloc(sizeof(struct commit));
+               memset(ret, 0, sizeof(struct commit));
+               created_object(sha1, &ret->object);
+               return ret;
+       }
+       if (obj->parsed && obj->type != commit_type) {
+               error("Object %s is a %s, not a commit", 
+                     sha1_to_hex(sha1), obj->type);
+               return NULL;
+       }
+       return (struct commit *) obj;
+}
+
+static unsigned long parse_commit_date(const char *buf)
+{
+       unsigned long date;
+
+       if (memcmp(buf, "author", 6))
+               return 0;
+       while (*buf++ != '\n')
+               /* nada */;
+       if (memcmp(buf, "committer", 9))
+               return 0;
+       while (*buf++ != '>')
+               /* nada */;
+       date = strtoul(buf, NULL, 10);
+       if (date == ULONG_MAX)
+               date = 0;
+       return date;
+}
+
+int parse_commit(struct commit *item)
+{
+       char type[20];
+       void * buffer, *bufptr;
+       unsigned long size;
+       unsigned char parent[20];
+       if (item->object.parsed)
+               return 0;
+       item->object.parsed = 1;
+       buffer = bufptr = read_sha1_file(item->object.sha1, type, &size);
+       if (!buffer)
+               return error("Could not read %s",
+                            sha1_to_hex(item->object.sha1));
+       if (strcmp(type, commit_type))
+               return error("Object %s not a commit",
+                            sha1_to_hex(item->object.sha1));
+       item->object.type = commit_type;
+       get_sha1_hex(bufptr + 5, parent);
+       item->tree = lookup_tree(parent);
+       add_ref(&item->object, &item->tree->object);
+       bufptr += 46; /* "tree " + "hex sha1" + "\n" */
+       while (!memcmp(bufptr, "parent ", 7) &&
+              !get_sha1_hex(bufptr + 7, parent)) {
+               struct commit_list *new_parent = 
+                       malloc(sizeof(struct commit_list));
+               new_parent->next = item->parents;
+               new_parent->item = lookup_commit(parent);
+               add_ref(&item->object, &new_parent->item->object);
+               item->parents = new_parent;
+               bufptr += 48;
+       }
+       item->date = parse_commit_date(bufptr);
+       free(buffer);
+       return 0;
+}
+
+void free_commit_list(struct commit_list *list)
+{
+       while (list) {
+               struct commit_list *temp = list;
+               list = temp->next;
+               free(temp);
+       }
+}

diff --git a/object.c b/object.c
new file mode 100644 (file)
index 0000000..cfa2337
--- /dev/null
+++ b/object.c
@@ -0,0 +1,96 @@
+#include "object.h"
+#include "cache.h"
+#include <stdlib.h>
+#include <string.h>
+
+struct object **objs;
+int nr_objs;
+static int obj_allocs;
+
+static int find_object(unsigned char *sha1)
+{
+       int first = 0, last = nr_objs;
+
+        while (first < last) {
+                int next = (first + last) / 2;
+                struct object *obj = objs[next];
+                int cmp;
+
+                cmp = memcmp(sha1, obj->sha1, 20);
+                if (!cmp)
+                        return next;
+                if (cmp < 0) {
+                        last = next;
+                        continue;
+                }
+                first = next+1;
+        }
+        return -first-1;
+}
+
+struct object *lookup_object(unsigned char *sha1)
+{
+       int pos = find_object(sha1);
+       if (pos >= 0)
+               return objs[pos];
+       return NULL;
+}
+
+void created_object(unsigned char *sha1, struct object *obj)
+{
+       int pos = find_object(sha1);
+
+       obj->parsed = 0;
+       memcpy(obj->sha1, sha1, 20);
+       obj->type = NULL;
+       obj->refs = NULL;
+       obj->used = 0;
+
+       if (pos >= 0)
+               die("Inserting %s twice\n", sha1_to_hex(sha1));
+       pos = -pos-1;
+
+       if (obj_allocs == nr_objs) {
+               obj_allocs = alloc_nr(obj_allocs);
+               objs = realloc(objs, obj_allocs * sizeof(struct object *));
+       }
+
+       /* Insert it into the right place */
+       memmove(objs + pos + 1, objs + pos, (nr_objs - pos) * 
+               sizeof(struct object *));
+
+       objs[pos] = obj;
+       nr_objs++;
+}
+
+void add_ref(struct object *refer, struct object *target)
+{
+       struct object_list **pp = &refer->refs;
+       struct object_list *p;
+       
+       while ((p = *pp) != NULL) {
+               if (p->item == target)
+                       return;
+               pp = &p->next;
+       }
+
+       target->used = 1;
+       p = malloc(sizeof(*p));
+       p->item = target;
+       p->next = NULL;
+       *pp = p;
+}
+
+void mark_reachable(struct object *obj, unsigned int mask)
+{
+       struct object_list *p = obj->refs;
+
+       /* If we've been here already, don't bother */
+       if (obj->flags & mask)
+               return;
+       obj->flags |= mask;
+       while (p) {
+               mark_reachable(p->item, mask);
+               p = p->next;
+       }
+}

diff --git a/tree.c b/tree.c
new file mode 100644 (file)
index 0000000..1aee098
--- /dev/null
+++ b/tree.c
@@ -0,0 +1,67 @@
+#include "tree.h"
+#include "blob.h"
+#include "cache.h"
+#include <stdlib.h>
+
+const char *tree_type = "tree";
+
+struct tree *lookup_tree(unsigned char *sha1)
+{
+       struct object *obj = lookup_object(sha1);
+       if (!obj) {
+               struct tree *ret = malloc(sizeof(struct tree));
+               memset(ret, 0, sizeof(struct tree));
+               created_object(sha1, &ret->object);
+               return ret;
+       }
+       if (obj->parsed && obj->type != tree_type) {
+               error("Object %s is a %s, not a tree", 
+                     sha1_to_hex(sha1), obj->type);
+               return NULL;
+       }
+       return (struct tree *) obj;
+}
+
+int parse_tree(struct tree *item)
+{
+       char type[20];
+       void *buffer, *bufptr;
+       unsigned long size;
+       if (item->object.parsed)
+               return 0;
+       item->object.parsed = 1;
+       item->object.type = tree_type;
+       buffer = bufptr = read_sha1_file(item->object.sha1, type, &size);
+       if (!buffer)
+               return error("Could not read %s",
+                            sha1_to_hex(item->object.sha1));
+       if (strcmp(type, tree_type))
+               return error("Object %s not a tree",
+                            sha1_to_hex(item->object.sha1));
+       while (size) {
+               struct object *obj;
+               int len = 1+strlen(bufptr);
+               unsigned char *file_sha1 = bufptr + len;
+               char *path = strchr(bufptr, ' ');
+               unsigned int mode;
+               if (size < len + 20 || !path || 
+                   sscanf(bufptr, "%o", &mode) != 1)
+                       return -1;
+
+               /* Warn about trees that don't do the recursive thing.. */
+               if (strchr(path, '/')) {
+                       item->has_full_path = 1;
+               }
+
+               bufptr += len + 20;
+               size -= len + 20;
+
+               if (S_ISDIR(mode)) {
+                       obj = &lookup_tree(file_sha1)->object;
+               } else {
+                       obj = &lookup_blob(file_sha1)->object;
+               }
+               add_ref(&item->object, obj);
+       }
+       return 0;
+}