X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=read-cache.c;h=8e90d2c3b6ae056d2b8f0410b4f12f0992bb7baf;hb=f864ba7448564d06e8076d1b6a66eca00a337d8c;hp=53da50065d75019d35610f480d9708247f4e0cf6;hpb=73134b6d3f700bb9e6c66aa2f099de644c6b8d09;p=git.git

diff --git a/read-cache.c b/read-cache.c
index 53da5006..8e90d2c3 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3,22 +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;
+	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);
+}
 
-	va_start(args, err);
-	vfprintf(stderr, err, args);
-	va_end(args);
+void die(const char *err, ...)
+{
+	va_list params;
+
+	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')
@@ -111,7 +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);
@@ -208,34 +233,70 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 	return 0;
 }
 
+static inline int collision_check(char *filename, void *buf, unsigned int size)
+{
+#ifdef COLLISION_CHECK
+	void *map;
+	int fd = open(filename, O_RDONLY);
+	struct stat st;
+	int cmp;
+
+	/* Unreadable object, or object went away? Strange. */
+	if (fd < 0)
+		return -1;
+
+	if (fstat(fd, &st) < 0 || size != st.st_size)
+		return -1;
+
+	map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+	close(fd);
+	if (map == MAP_FAILED)
+		return -1;
+	cmp = memcmp(buf, map, size);
+	munmap(map, size);
+	if (cmp)
+		return -1;
+#endif
+	return 0;
+}
+
 int write_sha1_buffer(const unsigned char *sha1, void *buf, unsigned int size)
 {
 	char *filename = sha1_file_name(sha1);
 	int fd;
 
 	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
-	if (fd < 0)
-		return (errno == EEXIST) ? 0 : -1;
+	if (fd < 0) {
+		if (errno != EEXIST)
+			return -1;
+		if (collision_check(filename, buf, size))
+			return error("SHA1 collision detected!"
+					" This is bad, bad, BAD!\a\n");
+		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)
@@ -276,24 +337,23 @@ int cache_name_pos(const char *name, int namelen)
 		struct cache_entry *ce = active_cache[next];
 		int cmp = cache_name_compare(name, namelen, ce->name, ce->namelen);
 		if (!cmp)
-			return -next-1;
+			return next;
 		if (cmp < 0) {
 			last = next;
 			continue;
 		}
 		first = next+1;
 	}
-	return first;
+	return -first-1;
 }
 
 int remove_file_from_cache(char *path)
 {
 	int pos = cache_name_pos(path, strlen(path));
-	if (pos < 0) {
-		pos = -pos-1;
+	if (pos >= 0) {
 		active_nr--;
 		if (pos < active_nr)
-			memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos - 1) * sizeof(struct cache_entry *));
+			memmove(active_cache + pos, active_cache + pos + 1, (active_nr - pos) * sizeof(struct cache_entry *));
 	}
 	return 0;
 }
@@ -305,10 +365,11 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
 	pos = cache_name_pos(ce->name, ce->namelen);
 
 	/* existing match? Just replace it */
-	if (pos < 0) {
-		active_cache[-pos-1] = ce;
+	if (pos >= 0) {
+		active_cache[pos] = ce;
 		return 0;
 	}
+	pos = -pos-1;
 
 	if (!ok_to_add)
 		return -1;
@@ -362,7 +423,7 @@ 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");