From 8966a39483fb2e823055b1c7f1a2ff9394d727e4 Mon Sep 17 00:00:00 2001 From: Jonathan Tan Date: Thu, 20 Oct 2016 14:39:47 -0700 Subject: trailer: use list.h for doubly-linked list Replace the existing handwritten implementation of a doubly-linked list in trailer.c with the functions and macros from list.h. This significantly simplifies the code. Signed-off-by: Jonathan Tan Signed-off-by: Ramsay Jones Signed-off-by: Junio C Hamano --- trailer.c | 258 ++++++++++++++++++++++---------------------------------------- 1 file changed, 91 insertions(+), 167 deletions(-) diff --git a/trailer.c b/trailer.c index 1f191b20b2..0b3716f514 100644 --- a/trailer.c +++ b/trailer.c @@ -4,6 +4,7 @@ #include "commit.h" #include "tempfile.h" #include "trailer.h" +#include "list.h" /* * Copyright (c) 2013, 2014 Christian Couder */ @@ -25,19 +26,24 @@ struct conf_info { static struct conf_info default_conf_info; struct trailer_item { - struct trailer_item *previous; - struct trailer_item *next; + struct list_head list; char *token; char *value; struct conf_info conf; }; -static struct trailer_item *first_conf_item; +static LIST_HEAD(conf_head); static char *separators = ":"; #define TRAILER_ARG_STRING "$ARG" +/* Iterate over the elements of the list. */ +#define list_for_each_dir(pos, head, is_reverse) \ + for (pos = is_reverse ? (head)->prev : (head)->next; \ + pos != (head); \ + pos = is_reverse ? pos->prev : pos->next) + static int after_or_end(enum action_where where) { return (where == WHERE_AFTER) || (where == WHERE_END); @@ -120,101 +126,49 @@ static void print_tok_val(FILE *outfile, const char *tok, const char *val) fprintf(outfile, "%s%c %s\n", tok, separators[0], val); } -static void print_all(FILE *outfile, struct trailer_item *first, int trim_empty) +static void print_all(FILE *outfile, struct list_head *head, int trim_empty) { + struct list_head *pos; struct trailer_item *item; - for (item = first; item; item = item->next) { + list_for_each(pos, head) { + item = list_entry(pos, struct trailer_item, list); if (!trim_empty || strlen(item->value) > 0) print_tok_val(outfile, item->token, item->value); } } -static void update_last(struct trailer_item **last) -{ - if (*last) - while ((*last)->next != NULL) - *last = (*last)->next; -} - -static void update_first(struct trailer_item **first) -{ - if (*first) - while ((*first)->previous != NULL) - *first = (*first)->previous; -} - static void add_arg_to_input_list(struct trailer_item *on_tok, - struct trailer_item *arg_tok, - struct trailer_item **first, - struct trailer_item **last) -{ - if (after_or_end(arg_tok->conf.where)) { - arg_tok->next = on_tok->next; - on_tok->next = arg_tok; - arg_tok->previous = on_tok; - if (arg_tok->next) - arg_tok->next->previous = arg_tok; - update_last(last); - } else { - arg_tok->previous = on_tok->previous; - on_tok->previous = arg_tok; - arg_tok->next = on_tok; - if (arg_tok->previous) - arg_tok->previous->next = arg_tok; - update_first(first); - } + struct trailer_item *arg_tok) +{ + if (after_or_end(arg_tok->conf.where)) + list_add(&arg_tok->list, &on_tok->list); + else + list_add_tail(&arg_tok->list, &on_tok->list); } static int check_if_different(struct trailer_item *in_tok, struct trailer_item *arg_tok, - int check_all) + int check_all, + struct list_head *head) { enum action_where where = arg_tok->conf.where; + struct list_head *next_head; do { - if (!in_tok) - return 1; if (same_trailer(in_tok, arg_tok)) return 0; /* * if we want to add a trailer after another one, * we have to check those before this one */ - in_tok = after_or_end(where) ? in_tok->previous : in_tok->next; + next_head = after_or_end(where) ? in_tok->list.prev + : in_tok->list.next; + if (next_head == head) + break; + in_tok = list_entry(next_head, struct trailer_item, list); } while (check_all); return 1; } -static void remove_from_list(struct trailer_item *item, - struct trailer_item **first, - struct trailer_item **last) -{ - struct trailer_item *next = item->next; - struct trailer_item *previous = item->previous; - - if (next) { - item->next->previous = previous; - item->next = NULL; - } else if (last) - *last = previous; - - if (previous) { - item->previous->next = next; - item->previous = NULL; - } else if (first) - *first = next; -} - -static struct trailer_item *remove_first(struct trailer_item **first) -{ - struct trailer_item *item = *first; - *first = item->next; - if (item->next) { - item->next->previous = NULL; - item->next = NULL; - } - return item; -} - static char *apply_command(const char *command, const char *arg) { struct strbuf cmd = STRBUF_INIT; @@ -266,8 +220,7 @@ static void apply_item_command(struct trailer_item *in_tok, struct trailer_item static void apply_arg_if_exists(struct trailer_item *in_tok, struct trailer_item *arg_tok, struct trailer_item *on_tok, - struct trailer_item **in_tok_first, - struct trailer_item **in_tok_last) + struct list_head *head) { switch (arg_tok->conf.if_exists) { case EXISTS_DO_NOTHING: @@ -275,40 +228,34 @@ static void apply_arg_if_exists(struct trailer_item *in_tok, break; case EXISTS_REPLACE: apply_item_command(in_tok, arg_tok); - add_arg_to_input_list(on_tok, arg_tok, - in_tok_first, in_tok_last); - remove_from_list(in_tok, in_tok_first, in_tok_last); + add_arg_to_input_list(on_tok, arg_tok); + list_del(&in_tok->list); free_trailer_item(in_tok); break; case EXISTS_ADD: apply_item_command(in_tok, arg_tok); - add_arg_to_input_list(on_tok, arg_tok, - in_tok_first, in_tok_last); + add_arg_to_input_list(on_tok, arg_tok); break; case EXISTS_ADD_IF_DIFFERENT: apply_item_command(in_tok, arg_tok); - if (check_if_different(in_tok, arg_tok, 1)) - add_arg_to_input_list(on_tok, arg_tok, - in_tok_first, in_tok_last); + if (check_if_different(in_tok, arg_tok, 1, head)) + add_arg_to_input_list(on_tok, arg_tok); else free_trailer_item(arg_tok); break; case EXISTS_ADD_IF_DIFFERENT_NEIGHBOR: apply_item_command(in_tok, arg_tok); - if (check_if_different(on_tok, arg_tok, 0)) - add_arg_to_input_list(on_tok, arg_tok, - in_tok_first, in_tok_last); + if (check_if_different(on_tok, arg_tok, 0, head)) + add_arg_to_input_list(on_tok, arg_tok); else free_trailer_item(arg_tok); break; } } -static void apply_arg_if_missing(struct trailer_item **in_tok_first, - struct trailer_item **in_tok_last, +static void apply_arg_if_missing(struct list_head *head, struct trailer_item *arg_tok) { - struct trailer_item **in_tok; enum action_where where; switch (arg_tok->conf.if_missing) { @@ -317,68 +264,60 @@ static void apply_arg_if_missing(struct trailer_item **in_tok_first, break; case MISSING_ADD: where = arg_tok->conf.where; - in_tok = after_or_end(where) ? in_tok_last : in_tok_first; apply_item_command(NULL, arg_tok); - if (*in_tok) { - add_arg_to_input_list(*in_tok, arg_tok, - in_tok_first, in_tok_last); - } else { - *in_tok_first = arg_tok; - *in_tok_last = arg_tok; - } - break; + if (after_or_end(where)) + list_add_tail(&arg_tok->list, head); + else + list_add(&arg_tok->list, head); } } -static int find_same_and_apply_arg(struct trailer_item **in_tok_first, - struct trailer_item **in_tok_last, +static int find_same_and_apply_arg(struct list_head *head, struct trailer_item *arg_tok) { + struct list_head *pos; struct trailer_item *in_tok; struct trailer_item *on_tok; - struct trailer_item *following_tok; enum action_where where = arg_tok->conf.where; int middle = (where == WHERE_AFTER) || (where == WHERE_BEFORE); int backwards = after_or_end(where); - struct trailer_item *start_tok = backwards ? *in_tok_last : *in_tok_first; + struct trailer_item *start_tok; - for (in_tok = start_tok; in_tok; in_tok = following_tok) { - following_tok = backwards ? in_tok->previous : in_tok->next; + if (list_empty(head)) + return 0; + + start_tok = list_entry(backwards ? head->prev : head->next, + struct trailer_item, + list); + + list_for_each_dir(pos, head, backwards) { + in_tok = list_entry(pos, struct trailer_item, list); if (!same_token(in_tok, arg_tok)) continue; on_tok = middle ? in_tok : start_tok; - apply_arg_if_exists(in_tok, arg_tok, on_tok, - in_tok_first, in_tok_last); + apply_arg_if_exists(in_tok, arg_tok, on_tok, head); return 1; } return 0; } -static void process_trailers_lists(struct trailer_item **in_tok_first, - struct trailer_item **in_tok_last, - struct trailer_item **arg_tok_first) +static void process_trailers_lists(struct list_head *head, + struct list_head *arg_head) { + struct list_head *pos, *p; struct trailer_item *arg_tok; - struct trailer_item *next_arg; - - if (!*arg_tok_first) - return; - for (arg_tok = *arg_tok_first; arg_tok; arg_tok = next_arg) { + list_for_each_safe(pos, p, arg_head) { int applied = 0; + arg_tok = list_entry(pos, struct trailer_item, list); - next_arg = arg_tok->next; - remove_from_list(arg_tok, arg_tok_first, NULL); + list_del(pos); - applied = find_same_and_apply_arg(in_tok_first, - in_tok_last, - arg_tok); + applied = find_same_and_apply_arg(head, arg_tok); if (!applied) - apply_arg_if_missing(in_tok_first, - in_tok_last, - arg_tok); + apply_arg_if_missing(head, arg_tok); } } @@ -438,13 +377,12 @@ static void duplicate_conf(struct conf_info *dst, const struct conf_info *src) static struct trailer_item *get_conf_item(const char *name) { + struct list_head *pos; struct trailer_item *item; - struct trailer_item *previous; /* Look up item with same name */ - for (previous = NULL, item = first_conf_item; - item; - previous = item, item = item->next) { + list_for_each(pos, &conf_head) { + item = list_entry(pos, struct trailer_item, list); if (!strcasecmp(item->conf.name, name)) return item; } @@ -454,12 +392,7 @@ static struct trailer_item *get_conf_item(const char *name) duplicate_conf(&item->conf, &default_conf_info); item->conf.name = xstrdup(name); - if (!previous) - first_conf_item = item; - else { - previous->next = item; - item->previous = previous; - } + list_add_tail(&item->list, &conf_head); return item; } @@ -633,6 +566,7 @@ static struct trailer_item *create_trailer_item(const char *string) struct strbuf val = STRBUF_INIT; struct trailer_item *item; int tok_len; + struct list_head *pos; if (parse_trailer(&tok, &val, string)) return NULL; @@ -640,7 +574,8 @@ static struct trailer_item *create_trailer_item(const char *string) tok_len = token_len_without_separator(tok.buf, tok.len); /* Lookup if the token matches something in the config */ - for (item = first_conf_item; item; item = item->next) { + list_for_each(pos, &conf_head) { + item = list_entry(pos, struct trailer_item, list); if (token_matches_item(tok.buf, item, tok_len)) return new_trailer_item(item, strbuf_detach(&tok, NULL), @@ -652,44 +587,34 @@ static struct trailer_item *create_trailer_item(const char *string) strbuf_detach(&val, NULL)); } -static void add_trailer_item(struct trailer_item **first, - struct trailer_item **last, - struct trailer_item *new) +static void add_trailer_item(struct list_head *head, struct trailer_item *new) { if (!new) return; - if (!*last) { - *first = new; - *last = new; - } else { - (*last)->next = new; - new->previous = *last; - *last = new; - } + list_add_tail(&new->list, head); } -static struct trailer_item *process_command_line_args(struct string_list *trailers) +static void process_command_line_args(struct list_head *arg_head, + struct string_list *trailers) { - struct trailer_item *arg_tok_first = NULL; - struct trailer_item *arg_tok_last = NULL; struct string_list_item *tr; struct trailer_item *item; + struct list_head *pos; /* Add a trailer item for each configured trailer with a command */ - for (item = first_conf_item; item; item = item->next) { + list_for_each(pos, &conf_head) { + item = list_entry(pos, struct trailer_item, list); if (item->conf.command) { struct trailer_item *new = new_trailer_item(item, NULL, NULL); - add_trailer_item(&arg_tok_first, &arg_tok_last, new); + add_trailer_item(arg_head, new); } } /* Add a trailer item for each trailer on the command line */ for_each_string_list_item(tr, trailers) { struct trailer_item *new = create_trailer_item(tr->string); - add_trailer_item(&arg_tok_first, &arg_tok_last, new); + add_trailer_item(arg_head, new); } - - return arg_tok_first; } static struct strbuf **read_input_file(const char *file) @@ -805,8 +730,7 @@ static void print_lines(FILE *outfile, struct strbuf **lines, int start, int end static int process_input_file(FILE *outfile, struct strbuf **lines, - struct trailer_item **in_tok_first, - struct trailer_item **in_tok_last) + struct list_head *head) { int count = 0; int patch_start, trailer_start, trailer_end, i; @@ -829,18 +753,19 @@ static int process_input_file(FILE *outfile, for (i = trailer_start; i < trailer_end; i++) { if (lines[i]->buf[0] != comment_line_char) { struct trailer_item *new = create_trailer_item(lines[i]->buf); - add_trailer_item(in_tok_first, in_tok_last, new); + add_trailer_item(head, new); } } return trailer_end; } -static void free_all(struct trailer_item **first) +static void free_all(struct list_head *head) { - while (*first) { - struct trailer_item *item = remove_first(first); - free_trailer_item(item); + struct list_head *pos, *p; + list_for_each_safe(pos, p, head) { + list_del(pos); + free_trailer_item(list_entry(pos, struct trailer_item, list)); } } @@ -877,9 +802,8 @@ static FILE *create_in_place_tempfile(const char *file) void process_trailers(const char *file, int in_place, int trim_empty, struct string_list *trailers) { - struct trailer_item *in_tok_first = NULL; - struct trailer_item *in_tok_last = NULL; - struct trailer_item *arg_tok_first; + LIST_HEAD(head); + LIST_HEAD(arg_head); struct strbuf **lines; int trailer_end; FILE *outfile = stdout; @@ -894,15 +818,15 @@ void process_trailers(const char *file, int in_place, int trim_empty, struct str outfile = create_in_place_tempfile(file); /* Print the lines before the trailers */ - trailer_end = process_input_file(outfile, lines, &in_tok_first, &in_tok_last); + trailer_end = process_input_file(outfile, lines, &head); - arg_tok_first = process_command_line_args(trailers); + process_command_line_args(&arg_head, trailers); - process_trailers_lists(&in_tok_first, &in_tok_last, &arg_tok_first); + process_trailers_lists(&head, &arg_head); - print_all(outfile, in_tok_first, trim_empty); + print_all(outfile, &head, trim_empty); - free_all(&in_tok_first); + free_all(&head); /* Print the lines after the trailers as is */ print_lines(outfile, lines, trailer_end, INT_MAX); -- cgit v1.2.3