[PATCH] nsec portability

[git.git] / read-cache.c

diff --git a/read-cache.c b/read-cache.c
index 3c575f7..e3d3ddb 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -3,24 +3,47 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
+#include <stdarg.h>
 #include "cache.h"
 
 const char *sha1_file_directory = NULL;
 struct cache_entry **active_cache = NULL;
 unsigned int active_nr = 0, active_alloc = 0;
 
-void usage(const char *err, ...)
+void usage(const char *err)
 {
-       va_list args;
-       char string[200];
+       fprintf(stderr, "usage: %s\n", err);
+       exit(1);
+}
+
+static void report(const char *prefix, const char *err, va_list params)
+{
+       fputs(prefix, stderr);
+       vfprintf(stderr, err, params);
+       fputs("\n", stderr);
+}
+
+void die(const char *err, ...)
+{
+       va_list params;
 
-       va_start(args, err);
-       vsnprintf(string, sizeof(string), err, args);
-       va_end(args);
-       fprintf(stderr, "%s\n", string);
+       va_start(params, err);
+       report("fatal: ", err, params);
+       va_end(params);
        exit(1);
 }
 
+int error(const char *err, ...)
+{
+       va_list params;
+
+       va_start(params, err);
+       report("error: ", err, params);
+       va_end(params);
+       return -1;
+}
+
+
 static unsigned hexval(char c)
 {
        if (c >= '0' && c <= '9')
@@ -113,7 +136,7 @@ void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
                return NULL;
        }
        if (fstat(fd, &st) < 0) {
-               close(fd);  
+               close(fd);
                return NULL;
        }
        map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
@@ -216,28 +239,47 @@ int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
        int fd;
 
        fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-       if (fd < 0)
-               return (errno == EEXIST) ? 0 : -1;
+       if (fd < 0) {
+               void *map;
+
+               if (errno != EEXIST)
+                       return -1;
+#ifndef COLLISION_CHECK
+               fd = open(filename, O_RDONLY);
+               if (fd < 0)
+                       return -1;
+               map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+               if (map == MAP_FAILED)
+                       return -1;
+               if (memcmp(buf, map, size))
+                       return error("SHA1 collision detected!"
+                                       " This is bad, bad, BAD!\a\n");
+#endif
+               return 0;
+       }
        write(fd, buf, size);
        close(fd);
        return 0;
 }
 
-static int error(const char * string)
-{
-       fprintf(stderr, "error: %s\n", string);
-       return -1;
-}
-
 int cache_match_stat(struct cache_entry *ce, struct stat *st)
 {
        unsigned int changed = 0;
 
-       if (ce->mtime.sec  != (unsigned int)st->st_mtim.tv_sec ||
-           ce->mtime.nsec != (unsigned int)st->st_mtim.tv_nsec)
+       /* nsec seems unreliable - not all filesystems support it, so
+        * as long as it is in the inode cache you get right nsec
+        * but after it gets flushed, you get zero nsec. */
+       if (ce->mtime.sec  != (unsigned int)st->st_mtim.tv_sec
+#ifdef NSEC
+           || ce->mtime.nsec != (unsigned int)st->st_mtim.tv_nsec
+#endif
+           )
                changed |= MTIME_CHANGED;
-       if (ce->ctime.sec  != (unsigned int)st->st_ctim.tv_sec ||
-           ce->ctime.nsec != (unsigned int)st->st_ctim.tv_nsec)
+       if (ce->ctime.sec  != (unsigned int)st->st_ctim.tv_sec
+#ifdef NSEC
+           || ce->ctime.nsec != (unsigned int)st->st_ctim.tv_nsec
+#endif
+           )
                changed |= CTIME_CHANGED;
        if (ce->st_uid != (unsigned int)st->st_uid ||
            ce->st_gid != (unsigned int)st->st_gid)
@@ -364,7 +406,7 @@ int read_cache(void)
                sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
        if (access(sha1_file_directory, X_OK) < 0)
                return error("no access to SHA1 file directory");
-       fd = open(".dircache/index", O_RDONLY);
+       fd = open(".git/index", O_RDONLY);
        if (fd < 0)
                return (errno == ENOENT) ? 0 : error("open failed");