rebase: one safety net, one bugfix and one optimization.
[gitweb.git] / config.c
index 915bb9752374b8d11883fbe5da976e71e1b1af60..34584f62b40ef256d1d0f75e2ee16ed30b1c11fa 100644 (file)
--- a/config.c
+++ b/config.c
@@ -1,9 +1,17 @@
-
+/*
+ * GIT - The information manager from hell
+ *
+ * Copyright (C) Linus Torvalds, 2005
+ * Copyright (C) Johannes Schindelin, 2005
+ *
+ */
 #include "cache.h"
+#include <regex.h>
 
 #define MAXNAME (256)
 
 static FILE *config_file;
+static const char *config_file_name;
 static int config_linenr;
 static int get_next_char(void)
 {
@@ -136,7 +144,7 @@ static int get_base_var(char *name)
                        return -1;
                if (c == ']')
                        return baselen;
-               if (!isalnum(c))
+               if (!isalnum(c) && c != '.')
                        return -1;
                if (baselen > MAXNAME / 2)
                        return -1;
@@ -179,7 +187,7 @@ static int git_parse_file(config_fn_t fn)
                if (get_value(fn, var, baselen+1) < 0)
                        break;
        }
-       die("bad config file line %d", config_linenr);
+       die("bad config file line %d in %s", config_linenr, config_file_name);
 }
 
 int git_config_int(const char *name, const char *value)
@@ -190,7 +198,7 @@ int git_config_int(const char *name, const char *value)
                if (!*end)
                        return val;
        }
-       die("bad config value for '%s'", name);
+       die("bad config value for '%s' in %s", name, config_file_name);
 }
 
 int git_config_bool(const char *name, const char *value)
@@ -229,8 +237,8 @@ int git_default_config(const char *var, const char *value)
                return 0;
        }
 
-       if (!strcmp(var, "diff.renamelimit")) {
-               diff_rename_limit_default = git_config_int(var, value);
+       if (!strcmp(var, "i18n.commitencoding")) {
+               strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
                return 0;
        }
 
@@ -238,17 +246,348 @@ int git_default_config(const char *var, const char *value)
        return 0;
 }
 
-int git_config(config_fn_t fn)
+int git_config_from_file(config_fn_t fn, const char *filename)
 {
        int ret;
-       FILE *f = fopen(git_path("config"), "r");
+       FILE *f = fopen(filename, "r");
 
        ret = -1;
        if (f) {
                config_file = f;
+               config_file_name = filename;
                config_linenr = 1;
                ret = git_parse_file(fn);
                fclose(f);
+               config_file_name = NULL;
        }
        return ret;
 }
+
+int git_config(config_fn_t fn)
+{
+       return git_config_from_file(fn, git_path("config"));
+}
+
+/*
+ * Find all the stuff for git_config_set() below.
+ */
+
+#define MAX_MATCHES 512
+
+static struct {
+       int baselen;
+       char* key;
+       int do_not_match;
+       regex_t* value_regex;
+       int multi_replace;
+       off_t offset[MAX_MATCHES];
+       enum { START, SECTION_SEEN, SECTION_END_SEEN, KEY_SEEN } state;
+       int seen;
+} store;
+
+static int matches(const char* key, const char* value)
+{
+       return !strcmp(key, store.key) &&
+               (store.value_regex == NULL ||
+                (store.do_not_match ^
+                 !regexec(store.value_regex, value, 0, NULL, 0)));
+}
+
+static int store_aux(const char* key, const char* value)
+{
+       switch (store.state) {
+       case KEY_SEEN:
+               if (matches(key, value)) {
+                       if (store.seen == 1 && store.multi_replace == 0) {
+                               fprintf(stderr,
+                                       "Warning: %s has multiple values\n",
+                                       key);
+                       } else if (store.seen >= MAX_MATCHES) {
+                               fprintf(stderr, "Too many matches\n");
+                               return 1;
+                       }
+
+                       store.offset[store.seen] = ftell(config_file);
+                       store.seen++;
+               }
+               break;
+       case SECTION_SEEN:
+               if (strncmp(key, store.key, store.baselen+1)) {
+                       store.state = SECTION_END_SEEN;
+                       break;
+               } else
+                       /* do not increment matches: this is no match */
+                       store.offset[store.seen] = ftell(config_file);
+               /* fallthru */
+       case SECTION_END_SEEN:
+       case START:
+               if (matches(key, value)) {
+                       store.offset[store.seen] = ftell(config_file);
+                       store.state = KEY_SEEN;
+                       store.seen++;
+               } else if(!strncmp(key, store.key, store.baselen))
+                       store.state = SECTION_SEEN;
+       }
+       return 0;
+}
+
+static void store_write_section(int fd, const char* key)
+{
+       write(fd, "[", 1);
+       write(fd, key, store.baselen);
+       write(fd, "]\n", 2);
+}
+
+static void store_write_pair(int fd, const char* key, const char* value)
+{
+       int i;
+
+       write(fd, "\t", 1);
+       write(fd, key+store.baselen+1,
+               strlen(key+store.baselen+1));
+       write(fd, " = ", 3);
+       for (i = 0; value[i]; i++)
+               switch (value[i]) {
+               case '\n': write(fd, "\\n", 2); break;
+               case '\t': write(fd, "\\t", 2); break;
+               case '"': case '\\': write(fd, "\\", 1);
+               default: write(fd, value+i, 1);
+       }
+       write(fd, "\n", 1);
+}
+
+static int find_beginning_of_line(const char* contents, int size,
+       int offset_, int* found_bracket)
+{
+       int equal_offset = size, bracket_offset = size;
+       int offset;
+
+       for (offset = offset_-2; offset > 0 
+                       && contents[offset] != '\n'; offset--)
+               switch (contents[offset]) {
+                       case '=': equal_offset = offset; break;
+                       case ']': bracket_offset = offset; break;
+               }
+       if (bracket_offset < equal_offset) {
+               *found_bracket = 1;
+               offset = bracket_offset+1;
+       } else
+               offset++;
+
+       return offset;
+}
+
+int git_config_set(const char* key, const char* value)
+{
+       return git_config_set_multivar(key, value, NULL, 0);
+}
+
+/*
+ * If value==NULL, unset in (remove from) config,
+ * if value_regex!=NULL, disregard key/value pairs where value does not match.
+ * if multi_replace==0, nothing, or only one matching key/value is replaced,
+ *     else all matching key/values (regardless how many) are removed,
+ *     before the new pair is written.
+ *
+ * Returns 0 on success.
+ *
+ * This function does this:
+ *
+ * - it locks the config file by creating ".git/config.lock"
+ *
+ * - it then parses the config using store_aux() as validator to find
+ *   the position on the key/value pair to replace. If it is to be unset,
+ *   it must be found exactly once.
+ *
+ * - the config file is mmap()ed and the part before the match (if any) is
+ *   written to the lock file, then the changed part and the rest.
+ *
+ * - the config file is removed and the lock file rename()d to it.
+ *
+ */
+int git_config_set_multivar(const char* key, const char* value,
+       const char* value_regex, int multi_replace)
+{
+       int i;
+       struct stat st;
+       int fd;
+       char* config_filename = strdup(git_path("config"));
+       char* lock_file = strdup(git_path("config.lock"));
+       const char* last_dot = strrchr(key, '.');
+
+       /*
+        * Since "key" actually contains the section name and the real
+        * key name separated by a dot, we have to know where the dot is.
+        */
+
+       if (last_dot == NULL) { 
+               fprintf(stderr, "key does not contain a section: %s\n", key);
+               return 2;
+       }
+       store.baselen = last_dot - key;
+
+       store.multi_replace = multi_replace;
+
+       /*
+        * Validate the key and while at it, lower case it for matching.
+        */
+       store.key = (char*)malloc(strlen(key)+1);
+       for (i = 0; key[i]; i++)
+               if (i != store.baselen &&
+                               ((!isalnum(key[i]) && key[i] != '.') ||
+                                (i == store.baselen+1 && !isalpha(key[i])))) {
+                       fprintf(stderr, "invalid key: %s\n", key);
+                       free(store.key);
+                       return 1;
+               } else
+                       store.key[i] = tolower(key[i]);
+       store.key[i] = 0;
+
+       /*
+        * The lock_file serves a purpose in addition to locking: the new
+        * contents of .git/config will be written into it.
+        */
+       fd = open(lock_file, O_WRONLY | O_CREAT | O_EXCL, 0666);
+       if (fd < 0) {
+               fprintf(stderr, "could not lock config file\n");
+               free(store.key);
+               return -1;
+       }
+
+       /*
+        * If .git/config does not exist yet, write a minimal version.
+        */
+       if (stat(config_filename, &st)) {
+               static const char contents[] =
+                       "#\n"
+                       "# This is the config file\n"
+                       "#\n"
+                       "\n";
+
+               free(store.key);
+
+               /* if nothing to unset, error out */
+               if (value == NULL) {
+                       close(fd);
+                       unlink(lock_file);
+                       return 5;
+               }
+
+               store.key = (char*)key;
+
+               write(fd, contents, sizeof(contents)-1);
+               store_write_section(fd, key);
+               store_write_pair(fd, key, value);
+       } else{
+               int in_fd;
+               char* contents;
+               int i, copy_begin, copy_end, new_line = 0;
+
+               if (value_regex == NULL)
+                       store.value_regex = NULL;
+               else {
+                       if (value_regex[0] == '!') {
+                               store.do_not_match = 1;
+                               value_regex++;
+                       } else
+                               store.do_not_match = 0;
+
+                       store.value_regex = (regex_t*)malloc(sizeof(regex_t));
+                       if (regcomp(store.value_regex, value_regex,
+                                       REG_EXTENDED)) {
+                               fprintf(stderr, "Invalid pattern: %s",
+                                       value_regex);
+                               free(store.value_regex);
+                               return 6;
+                       }
+               }
+
+               store.offset[0] = 0;
+               store.state = START;
+               store.seen = 0;
+
+               /*
+                * After this, store.offset will contain the *end* offset
+                * of the last match, or remain at 0 if no match was found.
+                * As a side effect, we make sure to transform only a valid
+                * existing config file.
+                */
+               if (git_config(store_aux)) {
+                       fprintf(stderr, "invalid config file\n");
+                       free(store.key);
+                       if (store.value_regex != NULL) {
+                               regfree(store.value_regex);
+                               free(store.value_regex);
+                       }
+                       return 3;
+               }
+
+               free(store.key);
+               if (store.value_regex != NULL) {
+                       regfree(store.value_regex);
+                       free(store.value_regex);
+               }
+
+               /* if nothing to unset, or too many matches, error out */
+               if ((store.seen == 0 && value == NULL) ||
+                               (store.seen > 1 && multi_replace == 0)) {
+                       close(fd);
+                       unlink(lock_file);
+                       return 5;
+               }
+
+               in_fd = open(config_filename, O_RDONLY, 0666);
+               contents = mmap(NULL, st.st_size, PROT_READ,
+                       MAP_PRIVATE, in_fd, 0);
+               close(in_fd);
+
+               if (store.seen == 0)
+                       store.seen = 1;
+
+               for (i = 0, copy_begin = 0; i < store.seen; i++) {
+                       if (store.offset[i] == 0) {
+                               store.offset[i] = copy_end = st.st_size;
+                       } else if (store.state != KEY_SEEN) {
+                               copy_end = store.offset[i];
+                       } else
+                               copy_end = find_beginning_of_line(
+                                       contents, st.st_size,
+                                       store.offset[i]-2, &new_line);
+
+                       /* write the first part of the config */
+                       if (copy_end > copy_begin) {
+                               write(fd, contents + copy_begin,
+                               copy_end - copy_begin);
+                               if (new_line)
+                                       write(fd, "\n", 1);
+                       }
+                       copy_begin = store.offset[i];
+               }
+
+               /* write the pair (value == NULL means unset) */
+               if (value != NULL) {
+                       if (store.state == START)
+                               store_write_section(fd, key);
+                       store_write_pair(fd, key, value);
+               }
+
+               /* write the rest of the config */
+               if (copy_begin < st.st_size)
+                       write(fd, contents + copy_begin,
+                               st.st_size - copy_begin);
+
+               munmap(contents, st.st_size);
+               unlink(config_filename);
+       }
+
+       close(fd);
+
+       if (rename(lock_file, config_filename) < 0) {
+               fprintf(stderr, "Could not rename the lock file?\n");
+               return 4;
+       }
+
+       return 0;
+}
+
+