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authorDavid Barr <david.barr@cordelta.com>2010-11-28 13:45:01 -0600
committerJunio C Hamano <gitster@pobox.com>2010-12-01 13:27:37 -0800
commit85c62395b152f99e8867aaf84cea93dddc03243c (patch)
treee0c85a28a2ad00bb8d05536286bfc189dac3d962 /fast-import.c
parent4980fffb2c0848b354757ca270b4852363e9befa (diff)
downloadgit-85c62395b152f99e8867aaf84cea93dddc03243c.tar.gz
fast-import: let importers retrieve blobs
New objects written by fast-import are not available immediately. Until a checkpoint has been started and finishes writing the pack index, any new blobs will not be accessible using standard git tools. So introduce a new way to access them: a "cat-blob" command in the command stream requests for fast-import to print a blob to stdout or a file descriptor specified by the argument to --cat-blob-fd. The value for cat-blob-fd cannot be specified in the stream because that would be a layering violation: the decision of where to direct a stream has to be made when fast-import is started anyway, so we might as well make the stream format is independent of that detail. Output uses the same format as "git cat-file --batch". Thanks to Sverre Rabbelier and Sam Vilain for guidance in designing the protocol. Based-on-patch-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Acked-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'fast-import.c')
-rw-r--r--fast-import.c97
1 files changed, 97 insertions, 0 deletions
diff --git a/fast-import.c b/fast-import.c
index 4bd9bf7d08..dd58f517b9 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -55,6 +55,8 @@ Format of STDIN stream:
('from' sp committish lf)?
lf?;
+ cat_blob ::= 'cat-blob' sp (hexsha1 | idnum) lf;
+
checkpoint ::= 'checkpoint' lf
lf?;
@@ -361,6 +363,9 @@ static uintmax_t next_mark;
static struct strbuf new_data = STRBUF_INIT;
static int seen_data_command;
+/* Where to write output of cat-blob commands */
+static int cat_blob_fd = STDOUT_FILENO;
+
static void parse_argv(void);
static void write_branch_report(FILE *rpt, struct branch *b)
@@ -2689,6 +2694,81 @@ static void parse_reset_branch(void)
unread_command_buf = 1;
}
+static void cat_blob_write(const char *buf, unsigned long size)
+{
+ if (write_in_full(cat_blob_fd, buf, size) != size)
+ die_errno("Write to frontend failed");
+}
+
+static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
+{
+ struct strbuf line = STRBUF_INIT;
+ unsigned long size;
+ enum object_type type = 0;
+ char *buf;
+
+ if (!oe || oe->pack_id == MAX_PACK_ID) {
+ buf = read_sha1_file(sha1, &type, &size);
+ } else {
+ type = oe->type;
+ buf = gfi_unpack_entry(oe, &size);
+ }
+
+ /*
+ * Output based on batch_one_object() from cat-file.c.
+ */
+ if (type <= 0) {
+ strbuf_reset(&line);
+ strbuf_addf(&line, "%s missing\n", sha1_to_hex(sha1));
+ cat_blob_write(line.buf, line.len);
+ strbuf_release(&line);
+ free(buf);
+ return;
+ }
+ if (!buf)
+ die("Can't read object %s", sha1_to_hex(sha1));
+ if (type != OBJ_BLOB)
+ die("Object %s is a %s but a blob was expected.",
+ sha1_to_hex(sha1), typename(type));
+ strbuf_reset(&line);
+ strbuf_addf(&line, "%s %s %lu\n", sha1_to_hex(sha1),
+ typename(type), size);
+ cat_blob_write(line.buf, line.len);
+ strbuf_release(&line);
+ cat_blob_write(buf, size);
+ cat_blob_write("\n", 1);
+ free(buf);
+}
+
+static void parse_cat_blob(void)
+{
+ const char *p;
+ struct object_entry *oe = oe;
+ unsigned char sha1[20];
+
+ /* cat-blob SP <object> LF */
+ p = command_buf.buf + strlen("cat-blob ");
+ if (*p == ':') {
+ char *x;
+ oe = find_mark(strtoumax(p + 1, &x, 10));
+ if (x == p + 1)
+ die("Invalid mark: %s", command_buf.buf);
+ if (!oe)
+ die("Unknown mark: %s", command_buf.buf);
+ if (*x)
+ die("Garbage after mark: %s", command_buf.buf);
+ hashcpy(sha1, oe->idx.sha1);
+ } else {
+ if (get_sha1_hex(p, sha1))
+ die("Invalid SHA1: %s", command_buf.buf);
+ if (p[40])
+ die("Garbage after SHA1: %s", command_buf.buf);
+ oe = find_object(sha1);
+ }
+
+ cat_blob(oe, sha1);
+}
+
static void parse_checkpoint(void)
{
if (object_count) {
@@ -2773,6 +2853,14 @@ static void option_export_marks(const char *marks)
safe_create_leading_directories_const(export_marks_file);
}
+static void option_cat_blob_fd(const char *fd)
+{
+ unsigned long n = ulong_arg("--cat-blob-fd", fd);
+ if (n > (unsigned long) INT_MAX)
+ die("--cat-blob-fd cannot exceed %d", INT_MAX);
+ cat_blob_fd = (int) n;
+}
+
static void option_export_pack_edges(const char *edges)
{
if (pack_edges)
@@ -2826,6 +2914,8 @@ 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 (!strcmp(feature, "cat-blob")) {
+ ; /* Don't die - this feature is supported */
} else if (!prefixcmp(feature, "relative-marks")) {
relative_marks_paths = 1;
} else if (!prefixcmp(feature, "no-relative-marks")) {
@@ -2920,6 +3010,11 @@ static void parse_argv(void)
if (parse_one_feature(a + 2, 0))
continue;
+ if (!prefixcmp(a + 2, "cat-blob-fd=")) {
+ option_cat_blob_fd(a + 2 + strlen("cat-blob-fd="));
+ continue;
+ }
+
die("unknown option %s", a);
}
if (i != global_argc)
@@ -2971,6 +3066,8 @@ 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 "))