X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=read-cache.c;h=da2adf4612c3a1cb39fbb76e303302e9b7e1356b;hb=7ffeb8c24bb3eb83bf39e9d0348899f7f8178b2a;hp=bfa2de767a9be1dfb4c53ebc21784741c1f49b77;hpb=0fcfd160b0495c0881e142c546c4418b8cea7e93;p=git.git

diff --git a/read-cache.c b/read-cache.c
index bfa2de76..da2adf46 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -7,12 +7,25 @@
 #include "cache.h"
 
 struct cache_entry **active_cache = NULL;
-unsigned int active_nr = 0, active_alloc = 0;
+unsigned int active_nr = 0, active_alloc = 0, active_cache_changed = 0;
 
 int cache_match_stat(struct cache_entry *ce, struct stat *st)
 {
 	unsigned int changed = 0;
 
+	switch (ntohl(ce->ce_mode) & S_IFMT) {
+	case S_IFREG:
+		changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
+		/* We consider only the owner x bit to be relevant for "mode changes" */
+		if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
+			changed |= MODE_CHANGED;
+		break;
+	case S_IFLNK:
+		changed |= !S_ISLNK(st->st_mode) ? TYPE_CHANGED : 0;
+		break;
+	default:
+		die("internal error: ce_mode is %o", ntohl(ce->ce_mode));
+	}
 	if (ce->ce_mtime.sec != htonl(st->st_mtime))
 		changed |= MTIME_CHANGED;
 	if (ce->ce_ctime.sec != htonl(st->st_ctime))
@@ -24,18 +37,15 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st)
 	 * as long as it is in the inode cache you get right nsec
 	 * but after it gets flushed, you get zero nsec.
 	 */
-	if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec)
+	if (ce->ce_mtime.nsec != htonl(st->st_mtim.tv_nsec))
 		changed |= MTIME_CHANGED;
-	if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec)
+	if (ce->ce_ctime.nsec != htonl(st->st_ctim.tv_nsec))
 		changed |= CTIME_CHANGED;
 #endif	
 
 	if (ce->ce_uid != htonl(st->st_uid) ||
 	    ce->ce_gid != htonl(st->st_gid))
 		changed |= OWNER_CHANGED;
-	/* We consider only the owner x bit to be relevant for "mode changes" */
-	if (0100 & (ntohl(ce->ce_mode) ^ st->st_mode))
-		changed |= MODE_CHANGED;
 	if (ce->ce_dev != htonl(st->st_dev) ||
 	    ce->ce_ino != htonl(st->st_ino))
 		changed |= INODE_CHANGED;
@@ -87,8 +97,9 @@ int cache_name_pos(const char *name, int namelen)
 }
 
 /* Remove entry, return true if there are more entries to go.. */
-static int remove_entry_at(int pos)
+int remove_entry_at(int pos)
 {
+	active_cache_changed = 1;
 	active_nr--;
 	if (pos >= active_nr)
 		return 0;
@@ -106,20 +117,123 @@ int remove_file_from_cache(char *path)
 	return 0;
 }
 
-static int same_name(struct cache_entry *a, struct cache_entry *b)
+int same_name(struct cache_entry *a, struct cache_entry *b)
 {
 	int len = ce_namelen(a);
 	return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
 }
 
-int add_cache_entry(struct cache_entry *ce, int ok_to_add)
+/* We may be in a situation where we already have path/file and path
+ * is being added, or we already have path and path/file is being
+ * added.  Either one would result in a nonsense tree that has path
+ * twice when git-write-tree tries to write it out.  Prevent it.
+ * 
+ * If ok-to-replace is specified, we remove the conflicting entries
+ * from the cache so the caller should recompute the insert position.
+ * When this happens, we return non-zero.
+ */
+static int check_file_directory_conflict(const struct cache_entry *ce,
+					 int ok_to_replace)
 {
-	int pos;
+	int pos, replaced = 0;
+	const char *path = ce->name;
+	int namelen = strlen(path);
+	int stage = ce_stage(ce);
+	char *pathbuf = xmalloc(namelen + 1);
+	char *cp;
+
+	memcpy(pathbuf, path, namelen + 1);
+
+	/*
+	 * We are inserting path/file.  Do they have path registered at
+	 * the same stage?  We need to do this for all the levels of our
+	 * subpath.
+	 */
+	cp = pathbuf;
+	while (1) {
+		char *ep = strchr(cp, '/');
+		if (!ep)
+			break;
+		*ep = 0;    /* first cut it at slash */
+		pos = cache_name_pos(pathbuf,
+				     htons(create_ce_flags(ep-cp, stage)));
+		if (0 <= pos) {
+			/* Our leading path component is registered as a file,
+			 * and we are trying to make it a directory.  This is
+			 * bad.
+			 */
+			if (!ok_to_replace) {
+				free(pathbuf);
+				return -1;
+			}
+			fprintf(stderr, "removing file '%s' to replace it with a directory to create '%s'.\n", pathbuf, path);
+			remove_entry_at(pos);
+			replaced = 1;
+		}
+		*ep = '/';  /* then restore it and go downwards */
+		cp = ep + 1;
+	}
+	free(pathbuf);
+
+	/* Do we have an entry in the cache that makes our path a prefix
+	 * of it?  That is, are we creating a file where they already expect
+	 * a directory there?
+	 */
+	pos = cache_name_pos(path,
+			     htons(create_ce_flags(namelen, stage)));
 
+	/* (0 <= pos) cannot happen because add_cache_entry()
+	 * should have taken care of that case.
+	 */
+	pos = -pos-1;
+
+	/* pos would point at an existing entry that would come immediately
+	 * after our path.  It could be the same as our path in higher stage,
+	 * or different path but in a lower stage.
+	 *
+	 * E.g. when we are inserting path at stage 2,
+	 *
+	 *        1 path
+	 * pos->  3 path
+	 *        2 path/file1
+	 *        3 path/file1
+	 *        2 path/file2
+	 *        2 patho
+	 *
+	 * We need to examine pos, ignore it because it is at different
+	 * stage, examine next to find the path/file at stage 2, and
+	 * complain.  We need to do this until we are not the leading
+	 * path of an existing entry anymore.
+	 */
+
+	while (pos < active_nr) {
+		struct cache_entry *other = active_cache[pos];
+		if (strncmp(other->name, path, namelen))
+			break; /* it is not our "subdirectory" anymore */
+		if ((ce_stage(other) == stage) &&
+		    other->name[namelen] == '/') {
+			if (!ok_to_replace)
+				return -1;
+			fprintf(stderr, "removing file '%s' under '%s' to be replaced with a file\n", other->name, path);
+			remove_entry_at(pos);
+			replaced = 1;
+			continue; /* cycle without updating pos */
+		}
+		pos++;
+	}
+	return replaced;
+}
+
+int add_cache_entry(struct cache_entry *ce, int option)
+{
+	int pos;
+	int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
+	int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
 	pos = cache_name_pos(ce->name, htons(ce->ce_flags));
 
 	/* existing match? Just replace it */
 	if (pos >= 0) {
+		active_cache_changed = 1;
 		active_cache[pos] = ce;
 		return 0;
 	}
@@ -140,10 +254,17 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
 	if (!ok_to_add)
 		return -1;
 
+	if (check_file_directory_conflict(ce, ok_to_replace)) {
+		if (!ok_to_replace)
+			return -1;
+		pos = cache_name_pos(ce->name, htons(ce->ce_flags));
+		pos = -pos-1;
+	}
+
 	/* Make sure the array is big enough .. */
 	if (active_nr == active_alloc) {
 		active_alloc = alloc_nr(active_alloc);
-		active_cache = realloc(active_cache, active_alloc * sizeof(struct cache_entry *));
+		active_cache = xrealloc(active_cache, active_alloc * sizeof(struct cache_entry *));
 	}
 
 	/* Add it in.. */
@@ -151,6 +272,7 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
 	if (active_nr > pos)
 		memmove(active_cache + pos + 1, active_cache + pos, (active_nr - pos - 1) * sizeof(ce));
 	active_cache[pos] = ce;
+	active_cache_changed = 1;
 	return 0;
 }
 
@@ -161,14 +283,13 @@ static int verify_hdr(struct cache_header *hdr, unsigned long size)
 
 	if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
 		return error("bad signature");
-	if (hdr->hdr_version != htonl(1))
-		return error("bad version");
+	if (hdr->hdr_version != htonl(2))
+		return error("bad index version");
 	SHA1_Init(&c);
-	SHA1_Update(&c, hdr, offsetof(struct cache_header, sha1));
-	SHA1_Update(&c, hdr+1, size - sizeof(*hdr));
+	SHA1_Update(&c, hdr, size - 20);
 	SHA1_Final(sha1, &c);
-	if (memcmp(sha1, hdr->sha1, 20))
-		return error("bad header sha1");
+	if (memcmp(sha1, (void *)hdr + size - 20, 20))
+		return error("bad index file sha1 signature");
 	return 0;
 }
 
@@ -184,12 +305,7 @@ int read_cache(void)
 	if (active_cache)
 		return error("more than one cachefile");
 	errno = ENOENT;
-	sha1_file_directory = getenv(DB_ENVIRONMENT);
-	if (!sha1_file_directory)
-		sha1_file_directory = DEFAULT_DB_ENVIRONMENT;
-	if (access(sha1_file_directory, X_OK) < 0)
-		return error("no access to SHA1 file directory");
-	fd = open(".git/index", O_RDONLY);
+	fd = open(get_index_file(), O_RDONLY);
 	if (fd < 0)
 		return (errno == ENOENT) ? 0 : error("open failed");
 
@@ -198,8 +314,8 @@ int read_cache(void)
 	if (!fstat(fd, &st)) {
 		size = st.st_size;
 		errno = EINVAL;
-		if (size >= sizeof(struct cache_header))
-			map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
+		if (size >= sizeof(struct cache_header) + 20)
+			map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 	}
 	close(fd);
 	if (-1 == (int)(long)map)
@@ -227,6 +343,49 @@ unmap:
 	return error("verify header failed");
 }
 
+#define WRITE_BUFFER_SIZE 8192
+static char write_buffer[WRITE_BUFFER_SIZE];
+static unsigned long write_buffer_len;
+
+static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
+{
+	while (len) {
+		unsigned int buffered = write_buffer_len;
+		unsigned int partial = WRITE_BUFFER_SIZE - buffered;
+		if (partial > len)
+			partial = 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)
+				return -1;
+			buffered = 0;
+		}
+		write_buffer_len = buffered;
+		len -= partial;
+		data += partial;
+ 	}
+ 	return 0;
+}
+
+static int ce_flush(SHA_CTX *context, int fd)
+{
+	unsigned int left = write_buffer_len;
+
+	if (left) {
+		write_buffer_len = 0;
+		SHA1_Update(context, write_buffer, left);
+	}
+
+	/* 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;
+}
+
 int write_cache(int newfd, struct cache_entry **cache, int entries)
 {
 	SHA_CTX c;
@@ -234,26 +393,17 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
 	int i;
 
 	hdr.hdr_signature = htonl(CACHE_SIGNATURE);
-	hdr.hdr_version = htonl(1);
+	hdr.hdr_version = htonl(2);
 	hdr.hdr_entries = htonl(entries);
 
 	SHA1_Init(&c);
-	SHA1_Update(&c, &hdr, offsetof(struct cache_header, sha1));
-	for (i = 0; i < entries; i++) {
-		struct cache_entry *ce = cache[i];
-		int size = ce_size(ce);
-		SHA1_Update(&c, ce, size);
-	}
-	SHA1_Final(hdr.sha1, &c);
-
-	if (write(newfd, &hdr, sizeof(hdr)) != sizeof(hdr))
+	if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
 		return -1;
 
 	for (i = 0; i < entries; i++) {
 		struct cache_entry *ce = cache[i];
-		int size = ce_size(ce);
-		if (write(newfd, ce, size) != size)
+		if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
 			return -1;
 	}
-	return 0;
+	return ce_flush(&c, newfd);
 }