Document git-merge-cache -o
[git.git] / update-cache.c
index 68d2f95..2f5d620 100644 (file)
@@ -3,6 +3,7 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#include <signal.h>
 #include "cache.h"
 
 /*
  * like "update-cache *" and suddenly having all the object
  * files be revision controlled.
  */
-static int allow_add = 0, allow_remove = 0;
+static int allow_add = 0, allow_remove = 0, allow_replace = 0, not_new = 0;
 
-static int index_fd(unsigned char *sha1, int fd, struct stat *st)
+/* Three functions to allow overloaded pointer return; see linux/err.h */
+static inline void *ERR_PTR(long error)
 {
-       z_stream stream;
-       unsigned long size = st->st_size;
-       int max_out_bytes = size + 200;
-       void *out = malloc(max_out_bytes);
-       void *metadata = malloc(200);
-       void *in;
-       SHA_CTX c;
-
-       in = "";
-       if (size)
-               in = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-       close(fd);
-       if (!out || (int)(long)in == -1)
-               return -1;
-
-       memset(&stream, 0, sizeof(stream));
-       deflateInit(&stream, Z_BEST_COMPRESSION);
+       return (void *) error;
+}
 
-       /*
-        * ASCII size + nul byte
-        */     
-       stream.next_in = metadata;
-       stream.avail_in = 1+sprintf(metadata, "blob %lu", size);
-       stream.next_out = out;
-       stream.avail_out = max_out_bytes;
-       while (deflate(&stream, 0) == Z_OK)
-               /* nothing */;
+static inline long PTR_ERR(const void *ptr)
+{
+       return (long) ptr;
+}
 
-       /*
-        * File content
-        */
-       stream.next_in = in;
-       stream.avail_in = size;
-       while (deflate(&stream, Z_FINISH) == Z_OK)
-               /*nothing */;
-
-       deflateEnd(&stream);
-       
-       SHA1_Init(&c);
-       SHA1_Update(&c, out, stream.total_out);
-       SHA1_Final(sha1, &c);
-
-       return write_sha1_buffer(sha1, out, stream.total_out);
+static inline long IS_ERR(const void *ptr)
+{
+       return (unsigned long)ptr > (unsigned long)-1000L;
 }
 
 /*
@@ -83,36 +53,60 @@ static void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
 
 static int add_file_to_cache(char *path)
 {
-       int size, namelen;
+       int size, namelen, option, status;
        struct cache_entry *ce;
        struct stat st;
        int fd;
-
-       fd = open(path, O_RDONLY);
-       if (fd < 0) {
-               if (errno == ENOENT) {
+       char *target;
+
+       status = lstat(path, &st);
+       if (status < 0 || S_ISDIR(st.st_mode)) {
+               /* When we used to have "path" and now we want to add
+                * "path/file", we need a way to remove "path" before
+                * being able to add "path/file".  However,
+                * "git-update-cache --remove path" would not work.
+                * --force-remove can be used but this is more user
+                * friendly, especially since we can do the opposite
+                * case just fine without --force-remove.
+                */
+               if (status == 0 || (errno == ENOENT || errno == ENOTDIR)) {
                        if (allow_remove)
                                return remove_file_from_cache(path);
                }
                return -1;
        }
-       if (fstat(fd, &st) < 0) {
-               close(fd);
-               return -1;
-       }
        namelen = strlen(path);
        size = cache_entry_size(namelen);
-       ce = malloc(size);
+       ce = xmalloc(size);
        memset(ce, 0, size);
        memcpy(ce->name, path, namelen);
        fill_stat_cache_info(ce, &st);
        ce->ce_mode = create_ce_mode(st.st_mode);
        ce->ce_flags = htons(namelen);
-
-       if (index_fd(ce->sha1, fd, &st) < 0)
+       switch (st.st_mode & S_IFMT) {
+       case S_IFREG:
+               fd = open(path, O_RDONLY);
+               if (fd < 0)
+                       return -1;
+               if (index_fd(ce->sha1, fd, &st) < 0)
+                       return -1;
+               break;
+       case S_IFLNK:
+               target = xmalloc(st.st_size+1);
+               if (readlink(path, target, st.st_size+1) != st.st_size) {
+                       free(target);
+                       return -1;
+               }
+               if (write_sha1_file(target, st.st_size, "blob", ce->sha1))
+                       return -1;
+               free(target);
+               break;
+       default:
                return -1;
-
-       return add_cache_entry(ce, allow_add);
+       }
+       option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+       option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+       return add_cache_entry(ce, option);
 }
 
 static int match_data(int fd, void *buffer, unsigned long size)
@@ -150,6 +144,33 @@ static int compare_data(struct cache_entry *ce, unsigned long expected_size)
        return match;
 }
 
+static int compare_link(struct cache_entry *ce, unsigned long expected_size)
+{
+       int match = -1;
+       char *target;
+       void *buffer;
+       unsigned long size;
+       char type[10];
+       int len;
+
+       target = xmalloc(expected_size);
+       len = readlink(ce->name, target, expected_size);
+       if (len != expected_size) {
+               free(target);
+               return -1;
+       }
+       buffer = read_sha1_file(ce->sha1, type, &size);
+       if (!buffer) {
+               free(target);
+               return -1;
+       }
+       if (size == expected_size)
+               match = memcmp(buffer, target, size);
+       free(buffer);
+       free(target);
+       return match;
+}
+
 /*
  * "refresh" does not calculate a new sha1 file or bring the
  * cache up-to-date for mode/content changes. But what it
@@ -167,39 +188,51 @@ static struct cache_entry *refresh_entry(struct cache_entry *ce)
        struct cache_entry *updated;
        int changed, size;
 
-       if (stat(ce->name, &st) < 0)
-               return NULL;
+       if (lstat(ce->name, &st) < 0)
+               return ERR_PTR(-errno);
 
        changed = cache_match_stat(ce, &st);
        if (!changed)
                return ce;
 
        /*
-        * If the mode has changed, there's no point in trying
+        * If the mode or type has changed, there's no point in trying
         * to refresh the entry - it's not going to match
         */
-       if (changed & MODE_CHANGED)
-               return NULL;
-
-       if (compare_data(ce, st.st_size))
-               return NULL;
+       if (changed & (MODE_CHANGED | TYPE_CHANGED))
+               return ERR_PTR(-EINVAL);
+
+       switch (st.st_mode & S_IFMT) {
+       case S_IFREG:
+               if (compare_data(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       case S_IFLNK:
+               if (compare_link(ce, st.st_size))
+                       return ERR_PTR(-EINVAL);
+               break;
+       default:
+               return ERR_PTR(-EINVAL);
+       }
 
        size = ce_size(ce);
-       updated = malloc(size);
+       updated = xmalloc(size);
        memcpy(updated, ce, size);
        fill_stat_cache_info(updated, &st);
        return updated;
 }
 
-static void refresh_cache(void)
+static int refresh_cache(void)
 {
        int i;
+       int has_errors = 0;
 
        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce, *new;
                ce = active_cache[i];
                if (ce_stage(ce)) {
                        printf("%s: needs merge\n", ce->name);
+                       has_errors = 1;
                        while ((i < active_nr) &&
                               ! strcmp(active_cache[i]->name, ce->name))
                                i++;
@@ -208,12 +241,17 @@ static void refresh_cache(void)
                }
 
                new = refresh_entry(ce);
-               if (!new) {
-                       printf("%s: needs update\n", ce->name);
+               if (IS_ERR(new)) {
+                       if (!(not_new && PTR_ERR(new) == -ENOENT)) {
+                               printf("%s: needs update\n", ce->name);
+                               has_errors = 1;
+                       }
                        continue;
                }
+               active_cache_changed = 1;
                active_cache[i] = new;
        }
+       return has_errors;
 }
 
 /*
@@ -246,7 +284,7 @@ inside:
 
 static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 {
-       int size, len;
+       int size, len, option;
        unsigned int mode;
        unsigned char sha1[20];
        struct cache_entry *ce;
@@ -260,35 +298,47 @@ static int add_cacheinfo(char *arg1, char *arg2, char *arg3)
 
        len = strlen(arg3);
        size = cache_entry_size(len);
-       ce = malloc(size);
+       ce = xmalloc(size);
        memset(ce, 0, size);
 
        memcpy(ce->sha1, sha1, 20);
        memcpy(ce->name, arg3, len);
        ce->ce_flags = htons(len);
        ce->ce_mode = create_ce_mode(mode);
-       return add_cache_entry(ce, allow_add);
+       option = allow_add ? ADD_CACHE_OK_TO_ADD : 0;
+       option |= allow_replace ? ADD_CACHE_OK_TO_REPLACE : 0;
+       return add_cache_entry(ce, option);
 }
 
-static int remove_lock = 0;
+static const char *lockfile_name = NULL;
 
 static void remove_lock_file(void)
 {
-       if (remove_lock)
-               unlink(".git/index.lock");
+       if (lockfile_name)
+               unlink(lockfile_name);
+}
+
+static void remove_lock_file_on_signal(int signo)
+{
+       remove_lock_file();
 }
 
 int main(int argc, char **argv)
 {
-       int i, newfd, entries;
+       int i, newfd, entries, has_errors = 0;
        int allow_options = 1;
+       static char lockfile[MAXPATHLEN+1];
+       const char *indexfile = get_index_file();
+
+       snprintf(lockfile, sizeof(lockfile), "%s.lock", indexfile);
 
-       newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
+       newfd = open(lockfile, O_RDWR | O_CREAT | O_EXCL, 0600);
        if (newfd < 0)
                die("unable to create new cachefile");
 
+       signal(SIGINT, remove_lock_file_on_signal);
        atexit(remove_lock_file);
-       remove_lock = 1;
+       lockfile_name = lockfile;
 
        entries = read_cache();
        if (entries < 0)
@@ -306,20 +356,39 @@ int main(int argc, char **argv)
                                allow_add = 1;
                                continue;
                        }
+                       if (!strcmp(path, "--replace")) {
+                               allow_replace = 1;
+                               continue;
+                       }
                        if (!strcmp(path, "--remove")) {
                                allow_remove = 1;
                                continue;
                        }
                        if (!strcmp(path, "--refresh")) {
-                               refresh_cache();
+                               has_errors |= refresh_cache();
                                continue;
                        }
                        if (!strcmp(path, "--cacheinfo")) {
-                               if (i+3 >= argc || add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
+                               if (i+3 >= argc)
                                        die("update-cache: --cacheinfo <mode> <sha1> <path>");
+                               if (add_cacheinfo(argv[i+1], argv[i+2], argv[i+3]))
+                                       die("update-cache: --cacheinfo cannot add %s", argv[i+3]);
                                i += 3;
                                continue;
                        }
+                       if (!strcmp(path, "--force-remove")) {
+                               if (argc <= i + 1)
+                                       die("update-cache: --force-remove <path>");
+                               if (remove_file_from_cache(argv[i+1]))
+                                       die("update-cache: --force-remove cannot remove %s", argv[i+1]);
+                               i++;
+                               continue;
+                       }
+
+                       if (!strcmp(path, "--ignore-missing")) {
+                               not_new = 1;
+                               continue;
+                       }
                        die("unknown option %s", path);
                }
                if (!verify_path(path)) {
@@ -329,10 +398,9 @@ int main(int argc, char **argv)
                if (add_file_to_cache(path))
                        die("Unable to add %s to database", path);
        }
-       if (write_cache(newfd, active_cache, active_nr) ||
-           rename(".git/index.lock", ".git/index"))
+       if (write_cache(newfd, active_cache, active_nr) || rename(lockfile, indexfile))
                die("Unable to write new cachefile");
 
-       remove_lock = 0;
-       return 0;
+       lockfile_name = NULL;
+       return has_errors ? 1 : 0;
 }