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[PATCH 1/7] Teach fast-import to print the id of each imported commit

From
David Barr <david.barr@cordelta.com>
Date
Oct 12, 2010, 13:50 UTC
Message-ID
<1286891424-2067-2-git-send-email-david.barr@cordelta.com>
In-Reply-To
<1286891424-2067-1-git-send-email-david.barr@cordelta.com>
From: Jonathan Nieder <jrnieder@gmail.com>

For the svn importer, it would be useful to build a map from subversion revision numbers to git commits as the import takes place. This is particularly relevant because the subversion api sometimes represents as "copy this directory from this revision", and the importer needs to be able to access the corresponding trees. So (optionally) print each commit id when the corresponding object is written.

Unfortunately when each commit object is written, it is not yet accessible to the caller until a checkpoint has finished. A later patch will teach fast-import to directly pass on the relevant data on request, using the same channel.

Cc: Shawn O. Pearce <spearce@spearce.org>
Cc: Sverre Rabbelier <srabbelier@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 Documentation/git-fast-import.txt |   13 +++++++++++++
 fast-import.c                     |   18 ++++++++++++++++++
 t/t9300-fast-import.sh            |   36 ++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 0 deletions(-)
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 966ba4f..e217635 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -92,6 +92,18 @@ OPTIONS
 	--(no-)-relative-marks= with the --(import|export)-marks=
 	options.
 
+--report-fd=<fd>::
+	Print the 40-character object name for each commit to
+	the specified file descriptor before writing it to the
+	pack.  This information may be useful if the importer
+	needs to maintain a map from revisions in the source
+	repository to commit ids in the target repository
+	during the import.
++
+The described objects are not necessarily accessible
+using standard git plumbing tools until a little while
+after the next checkpoint.
+
 --export-pack-edges=<file>::
 	After creating a packfile, print a line of data to
 	<file> listing the filename of the packfile and the last
@@ -896,6 +908,7 @@ The following features are currently supported:
 * date-format
 * import-marks
 * export-marks
+* report-fd
 * relative-marks
 * no-relative-marks
 * force
diff --git a/fast-import.c b/fast-import.c
index 2317b0f..ef0cee7 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -361,6 +361,9 @@ static uintmax_t next_mark;
 static struct strbuf new_data = STRBUF_INIT;
 static int seen_data_command;
 
+/* Where to report commits */
+static int report_fd = -1;
+
 static void parse_argv(void);
 
 static void write_branch_report(FILE *rpt, struct branch *b)
@@ -2571,6 +2574,11 @@ static void parse_new_commit(void)
 
 	if (!store_object(OBJ_COMMIT, &new_data, NULL, b->sha1, next_mark))
 		b->pack_id = pack_id;
+	if (report_fd != -1) {
+		char *buf = sha1_to_hex(b->sha1);
+		buf[40] = '\n';
+		write_or_die(report_fd, buf, 41);
+	}
 	b->last_commit = object_count_by_type[OBJ_COMMIT];
 }
 
@@ -2755,6 +2763,14 @@ static void option_export_marks(const char *marks)
 	safe_create_leading_directories_const(export_marks_file);
 }
 
+static void option_report_fd(const char *fd)
+{
+	unsigned long n = strtoul(fd, NULL, 0);
+	if (n > (unsigned long) INT_MAX)
+		die("--report-fd cannot exceed %d", INT_MAX);
+	report_fd = (int) n;
+}
+
 static void option_export_pack_edges(const char *edges)
 {
 	if (pack_edges)
@@ -2808,6 +2824,8 @@ static int parse_one_feature(const char *feature, int from_stream)
 		option_import_marks(feature + 13, from_stream);
 	} else if (!prefixcmp(feature, "export-marks=")) {
 		option_export_marks(feature + 13);
+	} else if (!prefixcmp(feature, "report-fd=")) {
+		option_report_fd(feature + strlen("report-fd="));
 	} else if (!prefixcmp(feature, "relative-marks")) {
 		relative_marks_paths = 1;
 	} else if (!prefixcmp(feature, "no-relative-marks")) {
diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh
index 7c05920..4371308 100755
--- a/t/t9300-fast-import.sh
+++ b/t/t9300-fast-import.sh
@@ -1611,6 +1611,42 @@ test_expect_success 'R: feature no-relative-marks should be honoured' '
     test_cmp marks.new non-relative.out
 '
 
+test_expect_success 'setup: have pipes?' '
+	test_when_finished "rm -f frob" &&
+	if mkfifo frob
+	then
+		test_set_prereq PIPE
+	fi
+'
+
+test_expect_success PIPE 'R: fast-import --report-fd' '
+	cat >frontend <<-\FRONTEND_END &&
+	#!/bin/sh
+	cat <<EOF &&
+	commit refs/heads/printed
+	committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> $GIT_COMMITTER_DATE
+	data <<COMMIT
+	to be printed
+	COMMIT
+
+	from refs/heads/master
+	D file3
+
+	EOF
+
+	read cid <&3 &&
+	echo "$cid" >received
+	EOF
+	FRONTEND_END
+
+	mkfifo commits &&
+	test_when_finished "rm -f commits" &&
+	sh frontend 3<commits |
+	git fast-import --report-fd=3 3>commits &&
+	git rev-parse --verify printed >real &&
+	test_cmp real received
+'
+
 cat >input << EOF
 option git quiet
 blob

-- 
1.7.3.1
Previous: David BarrNext: Sverre Rabbelier
Message 2 of 28 in “Add support for subversion dump format v3”
  1. Add support for subversion dump format v3David Barr, Oct 12, 2010
  2. 1/7 Teach fast-import to print the id of each imported commitDavid Barr, Oct 12, 2010
  3. Sverre RabbelierOct 12, 2010
  4. Jonathan NiederOct 12, 2010
  5. Sverre RabbelierOct 12, 2010
  6. Jonathan NiederOct 12, 2010
  7. Jonathan NiederOct 12, 2010
  8. Sverre RabbelierOct 12, 2010
  9. 2/7 fast-import: Let importers retrieve the objects being writtenDavid Barr, Oct 12, 2010
  10. Jonathan NiederOct 12, 2010
  11. Sverre RabbelierOct 12, 2010
  12. Jonathan NiederOct 13, 2010
  13. Sverre RabbelierOct 13, 2010
  14. 3/7 fast-import: Allow cat command with empty pathDavid Barr, Oct 12, 2010
  15. Jonathan NiederOct 12, 2010
  16. 4/7 fast-import: Allow cat requests at arbitrary points in streamDavid Barr, Oct 12, 2010
  17. Jonathan NiederOct 12, 2010
  18. 5/7 vcs-svn: extend svndump to parse version 3 formatDavid Barr, Oct 12, 2010
  19. Jonathan NiederOct 12, 2010
  20. 6/7 vcs-svn: implement prop-delta handling.David Barr, Oct 12, 2010
  21. Jonathan NiederOct 12, 2010
  22. 7/7 svn-fe: Use the --report-fd featureDavid Barr, Oct 12, 2010
  23. Sverre RabbelierOct 12, 2010
  24. Jonathan NiederOct 12, 2010
  25. Sverre RabbelierOct 12, 2010
  26. Jonathan NiederOct 12, 2010
  27. Jonathan NiederOct 12, 2010
  28. Jonathan NiederOct 13, 2010

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