[PATCH v2 08/15] config: introduce an optional event stream while parsing
- From
Johannes Schindelin <johannes.schindelin@gmx.de>
- Date
- Apr 3, 2018, 16:28 UTC
- Message-ID
- <a38025bcbc07b83b578ff2f1cde786bdca0c918c.1522772789.git.johannes.schindelin@gmx.de>
- In-Reply-To
- <cover.1522772789.git.johannes.schindelin@gmx.de>
This extends our config parser so that it can optionally produce an event stream via callback function, where it reports e.g. when a comment was parsed, or a section header, etc.
This parser will be used subsequently to handle the scenarios better where removing config entries would make sections empty, or where a new entry could be added to an already-existing, empty section.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> --- config.c | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-------- config.h | 25 ++++++++++++++++ 2 files changed, 115 insertions(+), 12 deletions(-)
diff --git a/config.c b/config.c index f10f8c6f52f..4cd745f6628 100644 --- a/config.c +++ b/config.c @@ -653,7 +653,46 @@ static int get_base_var(struct strbuf *name) } } -static int git_parse_source(config_fn_t fn, void *data) +struct parse_event_data { + enum config_event_t previous_type; + size_t previous_offset; + const struct config_options *opts; +}; + +static inline int do_event(enum config_event_t type, + struct parse_event_data *data) +{ + size_t offset; + + if (!data->opts || !data->opts->event_fn) + return 0; + + if (type == CONFIG_EVENT_WHITESPACE && + data->previous_type == type) + return 0; + + offset = cf->do_ftell(cf); + /* + * At EOF, the parser always "inserts" an extra '\n', therefore + * the end offset of the event is the current file position, otherwise + * we will already have advanced to the next event. + */ + if (type != CONFIG_EVENT_EOF) + offset--; + + if (data->previous_type != CONFIG_EVENT_EOF && + data->opts->event_fn(data->previous_type, data->previous_offset, + offset, data->opts->event_fn_data) < 0) + return -1; + + data->previous_type = type; + data->previous_offset = offset; + + return 0; +} + +static int git_parse_source(config_fn_t fn, void *data, + const struct config_options *opts) { int comment = 0; int baselen = 0; @@ -664,8 +703,15 @@ static int git_parse_source(config_fn_t fn, void *data) /* U+FEFF Byte Order Mark in UTF8 */ const char *bomptr = utf8_bom; + /* For the parser event callback */ + struct parse_event_data event_data = { + CONFIG_EVENT_EOF, 0, opts + }; + for (;;) { - int c = get_next_char(); + int c; + + c = get_next_char(); if (bomptr && *bomptr) { /* We are at the file beginning; skip UTF8-encoded BOM * if present. Sane editors won't put this in on their @@ -682,18 +728,33 @@ static int git_parse_source(config_fn_t fn, void *data) } } if (c == '\n') { - if (cf->eof) + if (cf->eof) { + if (do_event(CONFIG_EVENT_EOF, &event_data) < 0) + return -1; return 0; + } + if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0) + return -1; comment = 0; continue; } - if (comment || isspace(c)) + if (comment) continue; + if (isspace(c)) { + if (do_event(CONFIG_EVENT_WHITESPACE, &event_data) < 0) + return -1; + continue; + } if (c == '#' || c == ';') { + if (do_event(CONFIG_EVENT_COMMENT, &event_data) < 0) + return -1; comment = 1; continue; } if (c == '[') { + if (do_event(CONFIG_EVENT_SECTION, &event_data) < 0) + return -1; + /* Reset prior to determining a new stem */ strbuf_reset(var); if (get_base_var(var) < 0 || var->len < 1) @@ -704,6 +765,10 @@ static int git_parse_source(config_fn_t fn, void *data) } if (!isalpha(c)) break; + + if (do_event(CONFIG_EVENT_ENTRY, &event_data) < 0) + return -1; + /* * Truncate the var name back to the section header * stem prior to grabbing the suffix part of the name @@ -715,6 +780,9 @@ static int git_parse_source(config_fn_t fn, void *data) break; } + if (do_event(CONFIG_EVENT_ERROR, &event_data) < 0) + return -1; + switch (cf->origin_type) { case CONFIG_ORIGIN_BLOB: error_msg = xstrfmt(_("bad config line %d in blob %s"), @@ -1398,7 +1466,8 @@ int git_default_config(const char *var, const char *value, void *dummy) * fgetc, ungetc, ftell of top need to be initialized before calling * this function. */ -static int do_config_from(struct config_source *top, config_fn_t fn, void *data) +static int do_config_from(struct config_source *top, config_fn_t fn, void *data, + const struct config_options *opts) { int ret; @@ -1410,7 +1479,7 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data) strbuf_init(&top->var, 1024); cf = top; - ret = git_parse_source(fn, data); + ret = git_parse_source(fn, data, opts); /* pop config-file parsing state stack */ strbuf_release(&top->value); @@ -1423,7 +1492,7 @@ static int do_config_from(struct config_source *top, config_fn_t fn, void *data) static int do_config_from_file(config_fn_t fn, const enum config_origin_type origin_type, const char *name, const char *path, FILE *f, - void *data) + void *data, const struct config_options *opts) { struct config_source top; @@ -1436,15 +1505,18 @@ static int do_config_from_file(config_fn_t fn, top.do_ungetc = config_file_ungetc; top.do_ftell = config_file_ftell; - return do_config_from(&top, fn, data); + return do_config_from(&top, fn, data, opts); } static int git_config_from_stdin(config_fn_t fn, void *data) { - return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin, data); + return do_config_from_file(fn, CONFIG_ORIGIN_STDIN, "", NULL, stdin, + data, NULL); } -int git_config_from_file(config_fn_t fn, const char *filename, void *data) +int git_config_from_file_with_options(config_fn_t fn, const char *filename, + void *data, + const struct config_options *opts) { int ret = -1; FILE *f; @@ -1452,13 +1524,19 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data) f = fopen_or_warn(filename, "r"); if (f) { flockfile(f); - ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename, filename, f, data); + ret = do_config_from_file(fn, CONFIG_ORIGIN_FILE, filename, + filename, f, data, opts); funlockfile(f); fclose(f); } return ret; } +int git_config_from_file(config_fn_t fn, const char *filename, void *data) +{ + return git_config_from_file_with_options(fn, filename, data, NULL); +} + int git_config_from_mem(config_fn_t fn, const enum config_origin_type origin_type, const char *name, const char *buf, size_t len, void *data) { @@ -1475,7 +1553,7 @@ int git_config_from_mem(config_fn_t fn, const enum config_origin_type origin_typ top.do_ungetc = config_buf_ungetc; top.do_ftell = config_buf_ftell; - return do_config_from(&top, fn, data); + return do_config_from(&top, fn, data, NULL); } int git_config_from_blob_oid(config_fn_t fn, diff --git a/config.h b/config.h index ef70a9cac1e..5a2394daae2 100644 --- a/config.h +++ b/config.h @@ -28,15 +28,40 @@ enum config_origin_type { CONFIG_ORIGIN_CMDLINE }; +enum config_event_t { + CONFIG_EVENT_SECTION, + CONFIG_EVENT_ENTRY, + CONFIG_EVENT_WHITESPACE, + CONFIG_EVENT_COMMENT, + CONFIG_EVENT_EOF, + CONFIG_EVENT_ERROR +}; + +/* + * The parser event function (if not NULL) is called with the event type and + * the begin/end offsets of the parsed elements. + * + * Note: for CONFIG_EVENT_ENTRY (i.e. config variables), the trailing newline + * character is considered part of the element. + */ +typedef int (*config_parser_event_fn_t)(enum config_event_t type, + size_t begin_offset, size_t end_offset, + void *event_fn_data); + struct config_options { unsigned int respect_includes : 1; const char *commondir; const char *git_dir; + config_parser_event_fn_t event_fn; + void *event_fn_data; }; typedef int (*config_fn_t)(const char *, const char *, void *); extern int git_default_config(const char *, const char *, void *); extern int git_config_from_file(config_fn_t fn, const char *, void *); +extern int git_config_from_file_with_options(config_fn_t fn, const char *, + void *, + const struct config_options *); extern int git_config_from_mem(config_fn_t fn, const enum config_origin_type, const char *name, const char *buf, size_t len, void *data); extern int git_config_from_blob_oid(config_fn_t fn, const char *name,
-- 2.16.2.windows.1.26.g2cc3565eb4b