fast-import: Allow cat-blob requests at arbitrary points in stream

The new rule: a "cat-blob" can be inserted wherever a comment is
allowed, which means at the start of any line except in the middle of
a "data" command.

This saves frontends from having to loop over everything they want to
commit in the next commit and cat-ing the necessary objects in
advance.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 5d8f60c7909e0fe3dbbdf900cc885115bc932dc8..534b2519b32b1d008e289639d5b5df4539d42117 100644 (file)
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -912,6 +912,10 @@ output uses the same format as `git cat-file --batch`:
        <contents> LF
 ====
 
+This command can be used anywhere in the stream that comments are
+accepted.  In particular, the `cat-blob` command can be used in the
+middle of a commit but not in the middle of a `data` command.
+
 `feature`
 ~~~~~~~~~
 Require that fast-import supports the specified feature, or abort if

diff --git a/fast-import.c b/fast-import.c
index dd58f517b9f0e30fcd232afffbdeca1831b1b1e2..f71ea3e7bc5e0fc110dec9f983f37bbfcef9855d 100644 (file)
--- a/fast-import.c
+++ b/fast-import.c
@@ -55,8 +55,6 @@ Format of STDIN stream:
     ('from' sp committish lf)?
     lf?;
 
-  cat_blob ::= 'cat-blob' sp (hexsha1 | idnum) lf;
-
   checkpoint ::= 'checkpoint' lf
     lf?;
 
@@ -134,14 +132,17 @@ Format of STDIN stream:
   ts    ::= # time since the epoch in seconds, ascii base10 notation;
   tz    ::= # GIT style timezone;
 
-     # note: comments may appear anywhere in the input, except
-     # within a data command.  Any form of the data command
-     # always escapes the related input from comment processing.
+     # note: comments and cat requests may appear anywhere
+     # in the input, except within a data command.  Any form
+     # of the data command always escapes the related input
+     # from comment processing.
      #
      # In case it is not clear, the '#' that starts the comment
      # must be the first character on that line (an lf
      # preceded it).
      #
+  cat_blob ::= 'cat-blob' sp (hexsha1 | idnum) lf;
+
   comment ::= '#' not_lf* lf;
   not_lf  ::= # Any byte that is not ASCII newline (LF);
 */
@@ -367,6 +368,7 @@ static int seen_data_command;
 static int cat_blob_fd = STDOUT_FILENO;
 
 static void parse_argv(void);
+static void parse_cat_blob(void);
 
 static void write_branch_report(FILE *rpt, struct branch *b)
 {
@@ -1785,7 +1787,6 @@ static void read_marks(void)
        fclose(f);
 }
 
-
 static int read_next_command(void)
 {
        static int stdin_eof = 0;
@@ -1795,7 +1796,7 @@ static int read_next_command(void)
                return EOF;
        }
 
-       do {
+       for (;;) {
                if (unread_command_buf) {
                        unread_command_buf = 0;
                } else {
@@ -1828,9 +1829,14 @@ static int read_next_command(void)
                        rc->prev->next = rc;
                        cmd_tail = rc;
                }
-       } while (command_buf.buf[0] == '#');
-
-       return 0;
+               if (!prefixcmp(command_buf.buf, "cat-blob ")) {
+                       parse_cat_blob();
+                       continue;
+               }
+               if (command_buf.buf[0] == '#')
+                       continue;
+               return 0;
+       }
 }
 
 static void skip_optional_lf(void)
@@ -3066,8 +3072,6 @@ int main(int argc, const char **argv)
                        parse_new_tag();
                else if (!prefixcmp(command_buf.buf, "reset "))
                        parse_reset_branch();
-               else if (!prefixcmp(command_buf.buf, "cat-blob "))
-                       parse_cat_blob();
                else if (!strcmp("checkpoint", command_buf.buf))
                        parse_checkpoint();
                else if (!prefixcmp(command_buf.buf, "progress "))

diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index a0162b73d9e63659f6ef9102daede32bce816f04..d615d04a32cd96cf2de5ccec3cd1a66dddca8620 100755 (executable)
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -1823,6 +1823,72 @@ test_expect_success PIPE 'R: copy using cat-file' '
        test_cmp big actual
 '
 
+test_expect_success PIPE 'R: print blob mid-commit' '
+       rm -f blobs &&
+       echo "A blob from _before_ the commit." >expect &&
+       mkfifo blobs &&
+       (
+               exec 3<blobs &&
+               cat <<-EOF &&
+               feature cat-blob
+               blob
+               mark :1
+               data <<BLOB
+               A blob from _before_ the commit.
+               BLOB
+               commit refs/heads/temporary
+               committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+               data <<COMMIT
+               Empty commit
+               COMMIT
+               cat-blob :1
+               EOF
+
+               read blob_id type size <&3 &&
+               dd if=/dev/stdin of=actual bs=$size count=1 <&3 &&
+               read newline <&3 &&
+
+               echo
+       ) |
+       git fast-import --cat-blob-fd=3 3>blobs &&
+       test_cmp expect actual
+'
+
+test_expect_success PIPE 'R: print staged blob within commit' '
+       rm -f blobs &&
+       echo "A blob from _within_ the commit." >expect &&
+       mkfifo blobs &&
+       (
+               exec 3<blobs &&
+               cat <<-EOF &&
+               feature cat-blob
+               commit refs/heads/within
+               committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+               data <<COMMIT
+               Empty commit
+               COMMIT
+               M 644 inline within
+               data <<BLOB
+               A blob from _within_ the commit.
+               BLOB
+               EOF
+
+               to_get=$(
+                       echo "A blob from _within_ the commit." |
+                       git hash-object --stdin
+               ) &&
+               echo "cat-blob $to_get" &&
+
+               read blob_id type size <&3 &&
+               dd if=/dev/stdin of=actual bs=$size count=1 <&3 &&
+               read newline <&3 &&
+
+               echo deleteall
+       ) |
+       git fast-import --cat-blob-fd=3 3>blobs &&
+       test_cmp expect actual
+'
+
 cat >input << EOF
 option git quiet
 blob