diff options
| -rw-r--r-- | Documentation/technical/api-sub-process.txt | 59 | ||||
| -rw-r--r-- | convert.c | 75 | ||||
| -rw-r--r-- | pkt-line.c | 19 | ||||
| -rw-r--r-- | pkt-line.h | 2 | ||||
| -rw-r--r-- | sub-process.c | 104 | ||||
| -rw-r--r-- | sub-process.h | 51 | ||||
| -rwxr-xr-x | t/t0021-conversion.sh | 2 |
7 files changed, 161 insertions, 151 deletions
diff --git a/Documentation/technical/api-sub-process.txt b/Documentation/technical/api-sub-process.txt deleted file mode 100644 index 793508cf3e..0000000000 --- a/Documentation/technical/api-sub-process.txt +++ /dev/null @@ -1,59 +0,0 @@ -sub-process API -=============== - -The sub-process API makes it possible to run background sub-processes -for the entire lifetime of a Git invocation. If Git needs to communicate -with an external process multiple times, then this can reduces the process -invocation overhead. Git and the sub-process communicate through stdin and -stdout. - -The sub-processes are kept in a hashmap by command name and looked up -via the subprocess_find_entry function. If an existing instance can not -be found then a new process should be created and started. When the -parent git command terminates, all sub-processes are also terminated. - -This API is based on the run-command API. - -Data structures ---------------- - -* `struct subprocess_entry` - -The sub-process structure. Members should not be accessed directly. - -Types ------ - -'int(*subprocess_start_fn)(struct subprocess_entry *entry)':: - - User-supplied function to initialize the sub-process. This is - typically used to negotiate the interface version and capabilities. - - -Functions ---------- - -`cmd2process_cmp`:: - - Function to test two subprocess hashmap entries for equality. - -`subprocess_start`:: - - Start a subprocess and add it to the subprocess hashmap. - -`subprocess_stop`:: - - Kill a subprocess and remove it from the subprocess hashmap. - -`subprocess_find_entry`:: - - Find a subprocess in the subprocess hashmap. - -`subprocess_get_child_process`:: - - Get the underlying `struct child_process` from a subprocess. - -`subprocess_read_status`:: - - Helper function to read packets looking for the last "status=<foo>" - key/value pair. @@ -513,78 +513,17 @@ static struct hashmap subprocess_map; static int start_multi_file_filter_fn(struct subprocess_entry *subprocess) { - int err, i; - struct cmd2process *entry = (struct cmd2process *)subprocess; - struct string_list cap_list = STRING_LIST_INIT_NODUP; - char *cap_buf; - const char *cap_name; - struct child_process *process = &subprocess->process; - const char *cmd = subprocess->cmd; - - static const struct { - const char *name; - unsigned int cap; - } known_caps[] = { + static int versions[] = {2, 0}; + static struct subprocess_capability capabilities[] = { { "clean", CAP_CLEAN }, { "smudge", CAP_SMUDGE }, { "delay", CAP_DELAY }, + { NULL, 0 } }; - - sigchain_push(SIGPIPE, SIG_IGN); - - err = packet_writel(process->in, "git-filter-client", "version=2", NULL); - if (err) - goto done; - - err = strcmp(packet_read_line(process->out, NULL), "git-filter-server"); - if (err) { - error("external filter '%s' does not support filter protocol version 2", cmd); - goto done; - } - err = strcmp(packet_read_line(process->out, NULL), "version=2"); - if (err) - goto done; - err = packet_read_line(process->out, NULL) != NULL; - if (err) - goto done; - - for (i = 0; i < ARRAY_SIZE(known_caps); ++i) { - err = packet_write_fmt_gently( - process->in, "capability=%s\n", known_caps[i].name); - if (err) - goto done; - } - err = packet_flush_gently(process->in); - if (err) - goto done; - - for (;;) { - cap_buf = packet_read_line(process->out, NULL); - if (!cap_buf) - break; - string_list_split_in_place(&cap_list, cap_buf, '=', 1); - - if (cap_list.nr != 2 || strcmp(cap_list.items[0].string, "capability")) - continue; - - cap_name = cap_list.items[1].string; - i = ARRAY_SIZE(known_caps) - 1; - while (i >= 0 && strcmp(cap_name, known_caps[i].name)) - i--; - - if (i >= 0) - entry->supported_capabilities |= known_caps[i].cap; - else - warning("external filter '%s' requested unsupported filter capability '%s'", - cmd, cap_name); - - string_list_clear(&cap_list, 0); - } - -done: - sigchain_pop(SIGPIPE); - - return err; + struct cmd2process *entry = (struct cmd2process *)subprocess; + return subprocess_handshake(subprocess, "git-filter", versions, NULL, + capabilities, + &entry->supported_capabilities); } static void handle_filter_error(const struct strbuf *filter_status, diff --git a/pkt-line.c b/pkt-line.c index 9d845ecc3c..7db9119573 100644 --- a/pkt-line.c +++ b/pkt-line.c @@ -171,25 +171,6 @@ int packet_write_fmt_gently(int fd, const char *fmt, ...) return status; } -int packet_writel(int fd, const char *line, ...) -{ - va_list args; - int err; - va_start(args, line); - for (;;) { - if (!line) - break; - if (strlen(line) > LARGE_PACKET_DATA_MAX) - return -1; - err = packet_write_fmt_gently(fd, "%s\n", line); - if (err) - return err; - line = va_arg(args, const char*); - } - va_end(args); - return packet_flush_gently(fd); -} - static int packet_write_gently(const int fd_out, const char *buf, size_t size) { static char packet_write_buffer[LARGE_PACKET_MAX]; diff --git a/pkt-line.h b/pkt-line.h index 450183b649..66ef610fc4 100644 --- a/pkt-line.h +++ b/pkt-line.h @@ -25,8 +25,6 @@ void packet_buf_flush(struct strbuf *buf); void packet_buf_write(struct strbuf *buf, const char *fmt, ...) __attribute__((format (printf, 2, 3))); int packet_flush_gently(int fd); int packet_write_fmt_gently(int fd, const char *fmt, ...) __attribute__((format (printf, 2, 3))); -LAST_ARG_MUST_BE_NULL -int packet_writel(int fd, const char *line, ...); int write_packetized_from_fd(int fd_in, int fd_out); int write_packetized_from_buf(const char *src_in, size_t len, int fd_out); diff --git a/sub-process.c b/sub-process.c index 6cbffa4406..6edb97c1c6 100644 --- a/sub-process.c +++ b/sub-process.c @@ -108,3 +108,107 @@ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, co hashmap_add(hashmap, entry); return 0; } + +static int handshake_version(struct child_process *process, + const char *welcome_prefix, int *versions, + int *chosen_version) +{ + int version_scratch; + int i; + char *line; + const char *p; + + if (!chosen_version) + chosen_version = &version_scratch; + + if (packet_write_fmt_gently(process->in, "%s-client\n", + welcome_prefix)) + return error("Could not write client identification"); + for (i = 0; versions[i]; i++) { + if (packet_write_fmt_gently(process->in, "version=%d\n", + versions[i])) + return error("Could not write requested version"); + } + if (packet_flush_gently(process->in)) + return error("Could not write flush packet"); + + if (!(line = packet_read_line(process->out, NULL)) || + !skip_prefix(line, welcome_prefix, &p) || + strcmp(p, "-server")) + return error("Unexpected line '%s', expected %s-server", + line ? line : "<flush packet>", welcome_prefix); + if (!(line = packet_read_line(process->out, NULL)) || + !skip_prefix(line, "version=", &p) || + strtol_i(p, 10, chosen_version)) + return error("Unexpected line '%s', expected version", + line ? line : "<flush packet>"); + if ((line = packet_read_line(process->out, NULL))) + return error("Unexpected line '%s', expected flush", line); + + /* Check to make sure that the version received is supported */ + for (i = 0; versions[i]; i++) { + if (versions[i] == *chosen_version) + break; + } + if (!versions[i]) + return error("Version %d not supported", *chosen_version); + + return 0; +} + +static int handshake_capabilities(struct child_process *process, + struct subprocess_capability *capabilities, + unsigned int *supported_capabilities) +{ + int i; + char *line; + + for (i = 0; capabilities[i].name; i++) { + if (packet_write_fmt_gently(process->in, "capability=%s\n", + capabilities[i].name)) + return error("Could not write requested capability"); + } + if (packet_flush_gently(process->in)) + return error("Could not write flush packet"); + + while ((line = packet_read_line(process->out, NULL))) { + const char *p; + if (!skip_prefix(line, "capability=", &p)) + continue; + + for (i = 0; + capabilities[i].name && strcmp(p, capabilities[i].name); + i++) + ; + if (capabilities[i].name) { + if (supported_capabilities) + *supported_capabilities |= capabilities[i].flag; + } else { + warning("external filter requested unsupported filter capability '%s'", + p); + } + } + + return 0; +} + +int subprocess_handshake(struct subprocess_entry *entry, + const char *welcome_prefix, + int *versions, + int *chosen_version, + struct subprocess_capability *capabilities, + unsigned int *supported_capabilities) +{ + int retval; + struct child_process *process = &entry->process; + + sigchain_push(SIGPIPE, SIG_IGN); + + retval = handshake_version(process, welcome_prefix, versions, + chosen_version) || + handshake_capabilities(process, capabilities, + supported_capabilities); + + sigchain_pop(SIGPIPE); + return retval; +} diff --git a/sub-process.h b/sub-process.h index 8cd07a59ab..49701998c9 100644 --- a/sub-process.h +++ b/sub-process.h @@ -6,35 +6,66 @@ #include "run-command.h" /* - * Generic implementation of background process infrastructure. - * See: Documentation/technical/api-sub-process.txt + * The sub-process API makes it possible to run background sub-processes + * for the entire lifetime of a Git invocation. If Git needs to communicate + * with an external process multiple times, then this can reduces the process + * invocation overhead. Git and the sub-process communicate through stdin and + * stdout. + * + * The sub-processes are kept in a hashmap by command name and looked up + * via the subprocess_find_entry function. If an existing instance can not + * be found then a new process should be created and started. When the + * parent git command terminates, all sub-processes are also terminated. + * + * This API is based on the run-command API. */ /* data structures */ +/* Members should not be accessed directly. */ struct subprocess_entry { struct hashmap_entry ent; /* must be the first member! */ const char *cmd; struct child_process process; }; +struct subprocess_capability { + const char *name; + + /* + * subprocess_handshake will "|=" this value to supported_capabilities + * if the server reports that it supports this capability. + */ + unsigned int flag; +}; + /* subprocess functions */ +/* Function to test two subprocess hashmap entries for equality. */ extern int cmd2process_cmp(const void *unused_cmp_data, const void *e1, const void *e2, const void *unused_keydata); +/* + * User-supplied function to initialize the sub-process. This is + * typically used to negotiate the interface version and capabilities. + */ typedef int(*subprocess_start_fn)(struct subprocess_entry *entry); + +/* Start a subprocess and add it to the subprocess hashmap. */ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd, subprocess_start_fn startfn); +/* Kill a subprocess and remove it from the subprocess hashmap. */ void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry); +/* Find a subprocess in the subprocess hashmap. */ struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd); /* subprocess helper functions */ +/* Get the underlying `struct child_process` from a subprocess. */ static inline struct child_process *subprocess_get_child_process( struct subprocess_entry *entry) { @@ -42,6 +73,22 @@ static inline struct child_process *subprocess_get_child_process( } /* + * Perform the version and capability negotiation as described in the "Long + * Running Filter Process" section of the gitattributes documentation using the + * given requested versions and capabilities. The "versions" and "capabilities" + * parameters are arrays terminated by a 0 or blank struct. + * + * This function is typically called when a subprocess is started (as part of + * the "startfn" passed to subprocess_start). + */ +int subprocess_handshake(struct subprocess_entry *entry, + const char *welcome_prefix, + int *versions, + int *chosen_version, + struct subprocess_capability *capabilities, + unsigned int *supported_capabilities); + +/* * Helper function that will read packets looking for "status=<foo>" * key/value pairs and return the value from the last "status" packet */ diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh index eb3d83744a..46f8e583c3 100755 --- a/t/t0021-conversion.sh +++ b/t/t0021-conversion.sh @@ -697,7 +697,7 @@ test_expect_success PERL 'invalid process filter must fail (and not hang!)' ' cp "$TEST_ROOT/test.o" test.r && test_must_fail git add . 2>git-stderr.log && - grep "does not support filter protocol version" git-stderr.log + grep "expected git-filter-server" git-stderr.log ) ' |