The feature proposal of adding a command interface to cat-file was first
discussed in [A]. In [B], Taylor expressed the need for a fuller proposal
before moving forward with a new flag. An RFC was created [C] and the idea
was discussed more thoroughly, and overall it seemed like it was headed in
the right direction.
This patch series consolidates the feedback from these different threads.
This patch series has four parts:
1. preparation patch to rename a variable
2. adding an enum to keep track of batch modes
3. add a remove_timestamp() helper that takes stdin and removes timestamps
4. logic to handle --batch-command flag, adding contents, info, flush
commands
Changes since v7
* revert back to having caller set nr to 0
* add comment before dispatch_calls to clarify usage of helper
* rename prefix->name
Changes since v6 (thanks to Eric's feedback)
* allow command parsing logic to handle the case of flush as well
* fixed documentation by adding --batch-command to the synopsis and
adjusting tick marks
* set nr=0 within helper function
Changes since v5
* replaced flush tests that used fifo pipes to using a GIT_TEST_ env
variable to control whether or not --batch-command flushes on exit.
* added remove_timestamp helper in tests.
* added documentation to show format can be used with --batch-command
Changes since v4
* added Phillip's suggested test for testing flush. This should have
addressed the flaky test that was hanging. I tested it on my side and
wasn't able to reproduce the deadlock.
* plugged some holes in the logic that parsed the command and arguments,
thanks to Eric's feedback
* fixed verbiage in commit messages per Christian's feedback
* clarified places in documentation that should mention --batch-command per
Eric's feedback
Changes since v3 (thanks to Junio's feedback):
* added cascading logic in batch_options_callback()
* free memory for queued call input lines
* do not throw error when flushing an empty queue
* renamed cmds array to singular queued_cmd
* fixed flaky test that failed --stress
Changes since v2:
* added enum to keep track of which batch mode we are in (thanks to Junio's
feedback)
* fixed array allocation logic (thanks to Junio's feedback)
* added code to flush commands when --batch-commands receives an EOF and
exits (thanks to Phillip's feedback)
* fixed docs formatting (thanks to Jonathan's feedback)
Changes since v1:
* simplified "session" mechanism. "flush" will execute all commands that
were entered in since the last "flush" when in --buffer mode
* when not in --buffer mode, each command is executed and flushed each time
* rename cmdmode to transform_mode instead of just mode
* simplified command parsing logic
* changed rename of cmdmode to transform_mode
* clarified verbiage in commit messages
A. https://lore.kernel.org/git/xmqqk0hitnkc.fsf@gitster.g/ B.
https://lore.kernel.org/git/YehomwNiIs0l83W7@nand.local/ C.
https://lore.kernel.org/git/e75ba9ea-fdda-6e9f-4dd6-24190117d93b@xxxxxxxxx/
John Cai (4):
cat-file: rename cmdmode to transform_mode
cat-file: introduce batch_mode enum to replace print_contents
cat-file: add remove_timestamp helper
cat-file: add --batch-command mode
Documentation/git-cat-file.txt | 42 +++++++-
builtin/cat-file.c | 174 ++++++++++++++++++++++++++++++---
t/README | 3 +
t/t1006-cat-file.sh | 122 +++++++++++++++++++++--
4 files changed, 319 insertions(+), 22 deletions(-)
base-commit: 38062e73e009f27ea192d50481fcb5e7b0e9d6eb
Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1212%2Fjohn-cai%2Fjc-cat-file-batch-command-v8
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1212/john-cai/jc-cat-file-batch-command-v8
Pull-Request: https://github.com/git/git/pull/1212
Range-diff vs v7:
1: fa6294387ab = 1: fa6294387ab cat-file: rename cmdmode to transform_mode
2: 1a038097bfc = 2: 1a038097bfc cat-file: introduce batch_mode enum to replace print_contents
3: 486ee847816 = 3: 486ee847816 cat-file: add remove_timestamp helper
4: aebaf7e3fe1 ! 4: 8edf80574b8 cat-file: add --batch-command mode
@@ builtin/cat-file.c: static int batch_unordered_packed(const struct object_id *oi
+ batch_one_object(line, output, opt, data);
+}
+
++/* Loop through each queued_cmd, dispatch the function, free the
++ * memory associated with line so the cmd array can be reused.
++ * Callers must set nr back to 0 in order to reuse the cmd array.
++ */
+static void dispatch_calls(struct batch_options *opt,
+ struct strbuf *output,
+ struct expand_data *data,
+ struct queued_cmd *cmd,
-+ size_t *nr)
++ int nr)
+{
+ int i;
+
+ if (!opt->buffer_output)
+ die(_("flush is only for --buffer mode"));
+
-+ for (i = 0; i < *nr; i++) {
++ for (i = 0; i < nr; i++) {
+ cmd[i].fn(opt, cmd[i].line, output, data);
-+ free(cmd[i].line);
++ FREE_AND_NULL(cmd[i].line);
+ }
+
-+ *nr = 0;
+ fflush(stdout);
+}
+
+static const struct parse_cmd {
-+ const char *prefix;
++ const char *name;
+ parse_cmd_fn_t fn;
+ unsigned takes_args;
+} commands[] = {
@@ builtin/cat-file.c: static int batch_unordered_packed(const struct object_id *oi
+ die(_("whitespace before command: '%s'"), input.buf);
+
+ for (i = 0; i < ARRAY_SIZE(commands); i++) {
-+ if (!skip_prefix(input.buf, commands[i].prefix, &cmd_end))
++ if (!skip_prefix(input.buf, commands[i].name, &cmd_end))
+ continue;
+
+ cmd = &commands[i];
+ if (cmd->takes_args) {
+ if (*cmd_end != ' ')
+ die(_("%s requires arguments"),
-+ commands[i].prefix);
++ commands[i].name);
+
+ p = cmd_end + 1;
+ } else if (*cmd_end) {
+ die(_("%s takes no arguments"),
-+ commands[i].prefix);
++ commands[i].name);
+ }
+
+ break;
@@ builtin/cat-file.c: static int batch_unordered_packed(const struct object_id *oi
+ if (!cmd)
+ die(_("unknown command: '%s'"), input.buf);
+
-+ if (!strcmp(cmd->prefix, "flush")) {
-+ dispatch_calls(opt, output, data, queued_cmd, &nr);
++ if (!strcmp(cmd->name, "flush")) {
++ dispatch_calls(opt, output, data, queued_cmd, nr);
++ nr = 0;
+ continue;
+ }
+
@@ builtin/cat-file.c: static int batch_unordered_packed(const struct object_id *oi
+ if (opt->buffer_output &&
+ nr &&
+ !git_env_bool("GIT_TEST_CAT_FILE_NO_FLUSH_ON_EXIT", 0))
-+ dispatch_calls(opt, output, data, queued_cmd, &nr);
++ dispatch_calls(opt, output, data, queued_cmd, nr);
+
+ free(queued_cmd);
+ strbuf_release(&input);
--
gitgitgadget
