git-branch -D: make it work even when on a yet-to-be-born branch
[gitweb.git] / read-cache.c
index ce76c20f34fb0f976fe6264918e2945bbe4a19d6..eae4745d284e00e279b5b8f4b032bdb9ca433984 100644 (file)
@@ -5,7 +5,6 @@
  */
 #include "cache.h"
 #include "cache-tree.h"
-#include <time.h>
 
 /* Index extensions.
  *
 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
 #define CACHE_EXT_TREE 0x54524545      /* "TREE" */
 
-struct cache_entry **active_cache = NULL;
+struct cache_entry **active_cache;
 static time_t index_file_timestamp;
-unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
+unsigned int active_nr, active_alloc, active_cache_changed;
 
-struct cache_tree *active_cache_tree = NULL;
+struct cache_tree *active_cache_tree;
 
-int cache_errno = 0;
+int cache_errno;
 
-static void *cache_mmap = NULL;
-static size_t cache_mmap_size = 0;
+static void *cache_mmap;
+static size_t cache_mmap_size;
 
 /*
  * This only updates the "non-critical" parts of the directory
@@ -61,7 +60,7 @@ static int ce_compare_data(struct cache_entry *ce, struct stat *st)
        if (fd >= 0) {
                unsigned char sha1[20];
                if (!index_fd(sha1, fd, st, 0, NULL))
-                       match = memcmp(sha1, ce->sha1, 20);
+                       match = hashcmp(sha1, ce->sha1);
                /* index_fd() closed the file descriptor already */
        }
        return match;
@@ -170,9 +169,11 @@ static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
        return changed;
 }
 
-int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid)
+int ce_match_stat(struct cache_entry *ce, struct stat *st, int options)
 {
        unsigned int changed;
+       int ignore_valid = options & 01;
+       int assume_racy_is_modified = options & 02;
 
        /*
         * If it's marked as always valid in the index, it's
@@ -201,8 +202,12 @@ int ce_match_stat(struct cache_entry *ce, struct stat *st, int ignore_valid)
         */
        if (!changed &&
            index_file_timestamp &&
-           index_file_timestamp <= ntohl(ce->ce_mtime.sec))
-               changed |= ce_modified_check_fs(ce, st);
+           index_file_timestamp <= ntohl(ce->ce_mtime.sec)) {
+               if (assume_racy_is_modified)
+                       changed |= DATA_CHANGED;
+               else
+                       changed |= ce_modified_check_fs(ce, st);
+       }
 
        return changed;
 }
@@ -342,11 +347,13 @@ int add_file_to_index(const char *path, int verbose)
        ce->ce_mode = create_ce_mode(st.st_mode);
        if (!trust_executable_bit) {
                /* If there is an existing entry, pick the mode bits
-                * from it.
+                * from it, otherwise assume unexecutable.
                 */
                int pos = cache_name_pos(path, namelen);
                if (pos >= 0)
                        ce->ce_mode = active_cache[pos]->ce_mode;
+               else if (S_ISREG(st.st_mode))
+                       ce->ce_mode = create_ce_mode(S_IFREG | 0666);
        }
 
        if (index_path(ce->sha1, path, &st, 1))
@@ -739,7 +746,7 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
        SHA1_Init(&c);
        SHA1_Update(&c, hdr, size - 20);
        SHA1_Final(sha1, &c);
-       if (memcmp(sha1, (char *) hdr + size - 20, 20))
+       if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
                return error("bad index file sha1 signature");
        return 0;
 }
@@ -837,10 +844,39 @@ int read_cache_from(const char *path)
        die("index file corrupt");
 }
 
+int discard_cache(void)
+{
+       int ret;
+
+       active_nr = active_cache_changed = 0;
+       index_file_timestamp = 0;
+       cache_tree_free(&active_cache_tree);
+       if (cache_mmap == NULL)
+               return 0;
+       ret = munmap(cache_mmap, cache_mmap_size);
+       cache_mmap = NULL;
+       cache_mmap_size = 0;
+
+       /* no need to throw away allocated active_cache */
+       return ret;
+}
+
 #define WRITE_BUFFER_SIZE 8192
 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
 static unsigned long write_buffer_len;
 
+static int ce_write_flush(SHA_CTX *context, int fd)
+{
+       unsigned int buffered = write_buffer_len;
+       if (buffered) {
+               SHA1_Update(context, write_buffer, buffered);
+               if (write(fd, write_buffer, buffered) != buffered)
+                       return -1;
+               write_buffer_len = 0;
+       }
+       return 0;
+}
+
 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
 {
        while (len) {
@@ -851,8 +887,8 @@ static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
                memcpy(write_buffer + buffered, data, partial);
                buffered += partial;
                if (buffered == WRITE_BUFFER_SIZE) {
-                       SHA1_Update(context, write_buffer, WRITE_BUFFER_SIZE);
-                       if (write(fd, write_buffer, WRITE_BUFFER_SIZE) != WRITE_BUFFER_SIZE)
+                       write_buffer_len = buffered;
+                       if (ce_write_flush(context, fd))
                                return -1;
                        buffered = 0;
                }
@@ -868,10 +904,8 @@ static int write_index_ext_header(SHA_CTX *context, int fd,
 {
        ext = htonl(ext);
        sz = htonl(sz);
-       if ((ce_write(context, fd, &ext, 4) < 0) ||
-           (ce_write(context, fd, &sz, 4) < 0))
-               return -1;
-       return 0;
+       return ((ce_write(context, fd, &ext, 4) < 0) ||
+               (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
 }
 
 static int ce_flush(SHA_CTX *context, int fd)
@@ -893,9 +927,7 @@ static int ce_flush(SHA_CTX *context, int fd)
        /* Append the SHA1 signature at the end */
        SHA1_Final(write_buffer + left, context);
        left += 20;
-       if (write(fd, write_buffer, left) != left)
-               return -1;
-       return 0;
+       return (write(fd, write_buffer, left) != left) ? -1 : 0;
 }
 
 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
@@ -946,9 +978,7 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
 {
        SHA_CTX c;
        struct cache_header hdr;
-       int i, removed, recent;
-       struct stat st;
-       time_t now;
+       int i, removed;
 
        for (i = removed = 0; i < entries; i++)
                if (!cache[i]->ce_mode)
@@ -962,19 +992,15 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
        if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
                return -1;
 
-       now = fstat(newfd, &st) ? 0 : st.st_mtime;
-       recent = 0;
        for (i = 0; i < entries; i++) {
                struct cache_entry *ce = cache[i];
-               time_t entry_time = (time_t) ntohl(ce->ce_mtime.sec);
                if (!ce->ce_mode)
                        continue;
-               if (index_file_timestamp && index_file_timestamp <= entry_time)
+               if (index_file_timestamp &&
+                   index_file_timestamp <= ntohl(ce->ce_mtime.sec))
                        ce_smudge_racily_clean_entry(ce);
                if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
                        return -1;
-               if (now && now <= entry_time)
-                       recent++;
        }
 
        /* Write extension data here */
@@ -990,34 +1016,5 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
                        return -1;
                }
        }
-
-       /*
-        * To prevent later ce_match_stat() from always falling into
-        * check_fs(), if we have too many entries that can trigger
-        * racily clean check, we are better off delaying the return.
-        * We arbitrarily say if more than 20 paths or 25% of total
-        * paths are very new, we delay the return until the index
-        * file gets a new timestamp.
-        *
-        * NOTE! NOTE! NOTE!
-        *
-        * This assumes that nobody is touching the working tree while
-        * we are updating the index.
-        */
-       if (20 < recent || entries <= recent * 4) {
-               now = fstat(newfd, &st) ? 0 : st.st_mtime;
-               while (now && !fstat(newfd, &st) && st.st_mtime <= now) {
-                       struct timespec rq, rm;
-                       off_t where = lseek(newfd, 0, SEEK_CUR);
-                       rq.tv_sec = 0;
-                       rq.tv_nsec = 250000000;
-                       nanosleep(&rq, &rm);
-                       if ((where == (off_t) -1) ||
-                           (write(newfd, "", 1) != 1) ||
-                           (lseek(newfd, -1, SEEK_CUR) != where) ||
-                           ftruncate(newfd, where))
-                               break;
-               }
-       }
        return ce_flush(&c, newfd);
 }