From: Michael Haggerty Date: Wed, 1 Jul 2015 15:05:58 +0000 (+0200) Subject: fast-import: add a get-mark command X-Git-Tag: v2.6.0-rc0~98^2 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/28c7b1f7b7b70013c2f380c2d720d0c918d3d83a fast-import: add a get-mark command It is sometimes useful for importers to be able to read the SHA-1 corresponding to a mark that they have created via fast-import. For example, they might want to embed the SHA-1 into the commit message of a later commit. Or it might be useful for internal bookkeeping uses, or for logging. Add a "get-mark" command to "git fast-import" that allows the importer to ask for the value of a mark that has been created earlier. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano --- diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt index 690fed3ea4..c19b9ce557 100644 --- a/Documentation/git-fast-import.txt +++ b/Documentation/git-fast-import.txt @@ -54,7 +54,7 @@ Options for Frontends ~~~~~~~~~~~~~~~~~~~~~ --cat-blob-fd=:: - Write responses to `cat-blob` and `ls` queries to the + Write responses to `get-mark`, `cat-blob`, and `ls` queries to the file descriptor instead of `stdout`. Allows `progress` output intended for the end-user to be separated from other output. @@ -350,6 +350,11 @@ and control the current import process. More detailed discussion unless the `done` feature was requested using the `--done` command-line option or `feature done` command. +`get-mark`:: + Causes fast-import to print the SHA-1 corresponding to a mark + to the file descriptor set with `--cat-blob-fd`, or `stdout` if + unspecified. + `cat-blob`:: Causes fast-import to print a blob in 'cat-file --batch' format to the file descriptor set with `--cat-blob-fd` or @@ -930,6 +935,25 @@ Placing a `progress` command immediately after a `checkpoint` will inform the reader when the `checkpoint` has been completed and it can safely access the refs that fast-import updated. +`get-mark` +~~~~~~~~~~ +Causes fast-import to print the SHA-1 corresponding to a mark to +stdout or to the file descriptor previously arranged with the +`--cat-blob-fd` argument. The command otherwise has no impact on the +current import; its purpose is to retrieve SHA-1s that later commits +might want to refer to in their commit messages. + +.... + 'get-mark' SP ':' LF +.... + +This command can be used anywhere in the stream that comments are +accepted. In particular, the `get-mark` command can be used in the +middle of a commit but not in the middle of a `data` command. + +See ``Responses To Commands'' below for details about how to read +this output safely. + `cat-blob` ~~~~~~~~~~ Causes fast-import to print a blob to a file descriptor previously @@ -1000,7 +1024,8 @@ Output uses the same format as `git ls-tree -- `: ==== The represents the blob, tree, or commit object at -and can be used in later 'cat-blob', 'filemodify', or 'ls' commands. +and can be used in later 'get-mark', 'cat-blob', 'filemodify', or +'ls' commands. If there is no file or subtree at that path, 'git fast-import' will instead report @@ -1042,9 +1067,11 @@ import-marks-if-exists:: "feature import-marks-if-exists" like a corresponding command-line option silently skips a nonexistent file. +get-mark:: cat-blob:: ls:: - Require that the backend support the 'cat-blob' or 'ls' command. + Require that the backend support the 'get-mark', 'cat-blob', + or 'ls' command respectively. Versions of fast-import not supporting the specified command will exit with a message indicating so. This lets the import error out early with a clear message, @@ -1124,11 +1151,11 @@ bidirectional pipes: git fast-import >fast-import-output ==== -A frontend set up this way can use `progress`, `ls`, and `cat-blob` -commands to read information from the import in progress. +A frontend set up this way can use `progress`, `get-mark`, `ls`, and +`cat-blob` commands to read information from the import in progress. To avoid deadlock, such frontends must completely consume any -pending output from `progress`, `ls`, and `cat-blob` before +pending output from `progress`, `ls`, `get-mark`, and `cat-blob` before performing writes to fast-import that might block. Crash Reports diff --git a/fast-import.c b/fast-import.c index e78ca107b3..2b02f3f94d 100644 --- a/fast-import.c +++ b/fast-import.c @@ -134,16 +134,17 @@ Format of STDIN stream: ts ::= # time since the epoch in seconds, ascii base10 notation; tz ::= # GIT style timezone; - # note: comments, ls 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. + # note: comments, get-mark, ls-tree, and cat-blob 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). # + get_mark ::= 'get-mark' sp idnum lf; cat_blob ::= 'cat-blob' sp (hexsha1 | idnum) lf; ls_tree ::= 'ls' sp (hexsha1 | idnum) sp path_str lf; @@ -372,6 +373,7 @@ static volatile sig_atomic_t checkpoint_requested; static int cat_blob_fd = STDOUT_FILENO; static void parse_argv(void); +static void parse_get_mark(const char *p); static void parse_cat_blob(const char *p); static void parse_ls(const char *p, struct branch *b); @@ -1907,6 +1909,10 @@ static int read_next_command(void) rc->prev->next = rc; cmd_tail = rc; } + if (skip_prefix(command_buf.buf, "get-mark ", &p)) { + parse_get_mark(p); + continue; + } if (skip_prefix(command_buf.buf, "cat-blob ", &p)) { parse_cat_blob(p); continue; @@ -2919,6 +2925,23 @@ static void cat_blob(struct object_entry *oe, unsigned char sha1[20]) free(buf); } +static void parse_get_mark(const char *p) +{ + struct object_entry *oe = oe; + char output[42]; + + /* get-mark SP LF */ + if (*p != ':') + die("Not a mark: %s", p); + + oe = find_mark(parse_mark_ref_eol(p)); + if (!oe) + die("Unknown mark: %s", command_buf.buf); + + snprintf(output, sizeof(output), "%s\n", sha1_to_hex(oe->idx.sha1)); + cat_blob_write(output, 41); +} + static void parse_cat_blob(const char *p) { struct object_entry *oe = oe; @@ -3243,6 +3266,8 @@ static int parse_one_feature(const char *feature, int from_stream) option_import_marks(arg, from_stream, 1); } else if (skip_prefix(feature, "export-marks=", &arg)) { option_export_marks(arg); + } else if (!strcmp(feature, "get-mark")) { + ; /* Don't die - this feature is supported */ } else if (!strcmp(feature, "cat-blob")) { ; /* Don't die - this feature is supported */ } else if (!strcmp(feature, "relative-marks")) { diff --git a/t/t9300-fast-import.sh b/t/t9300-fast-import.sh index aac126fd57..9984c48b5a 100755 --- a/t/t9300-fast-import.sh +++ b/t/t9300-fast-import.sh @@ -2339,6 +2339,19 @@ test_expect_success !MINGW 'R: in-stream cat-blob-fd not respected' ' test_cmp expect actual.1 ' +test_expect_success !MINGW 'R: print mark for new blob' ' + echo "effluentish" | git hash-object --stdin >expect && + git fast-import --cat-blob-fd=6 6>actual <<-\EOF && + blob + mark :1 + data <expect <<-EOF &&