X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=read-cache.c;h=e9618f0914b36a4d1bd60785e53ad484e8748e36;hb=479346adc5ebb099121063d4c06da30093ed9b3b;hp=53f1da815bc2c23b25894663fa2cac17b08e64b2;hpb=520fc2415e83c0adfc1186ee922472c338cb4146;p=git.git

diff --git a/read-cache.c b/read-cache.c
index 53f1da81..e9618f09 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -3,22 +3,54 @@
  *
  * Copyright (C) Linus Torvalds, 2005
  */
-#include <stdarg.h>
 #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)
+/*
+ * This only updates the "non-critical" parts of the directory
+ * cache, ie the parts that aren't tracked by GIT, and only used
+ * to validate the cache.
+ */
+void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
+{
+	ce->ce_ctime.sec = htonl(st->st_ctime);
+	ce->ce_mtime.sec = htonl(st->st_mtime);
+#ifdef USE_NSEC
+	ce->ce_ctime.nsec = htonl(st->st_ctim.tv_nsec);
+	ce->ce_mtime.nsec = htonl(st->st_mtim.tv_nsec);
+#endif
+	ce->ce_dev = htonl(st->st_dev);
+	ce->ce_ino = htonl(st->st_ino);
+	ce->ce_uid = htonl(st->st_uid);
+	ce->ce_gid = htonl(st->st_gid);
+	ce->ce_size = htonl(st->st_size);
+}
+
+int ce_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))
 		changed |= CTIME_CHANGED;
 
-#ifdef NSEC
+#ifdef USE_NSEC
 	/*
 	 * nsec seems unreliable - not all filesystems support it, so
 	 * as long as it is in the inode cache you get right nsec
@@ -33,17 +65,43 @@ int cache_match_stat(struct cache_entry *ce, struct stat *st)
 	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))
+	if (ce->ce_ino != htonl(st->st_ino))
 		changed |= INODE_CHANGED;
+
+#ifdef USE_STDEV
+	/*
+	 * st_dev breaks on network filesystems where different
+	 * clients will have different views of what "device"
+	 * the filesystem is on
+	 */
+	if (ce->ce_dev != htonl(st->st_dev))
+		changed |= INODE_CHANGED;
+#endif
+
 	if (ce->ce_size != htonl(st->st_size))
 		changed |= DATA_CHANGED;
 	return changed;
 }
 
+int base_name_compare(const char *name1, int len1, int mode1,
+		      const char *name2, int len2, int mode2)
+{
+	unsigned char c1, c2;
+	int len = len1 < len2 ? len1 : len2;
+	int cmp;
+
+	cmp = memcmp(name1, name2, len);
+	if (cmp)
+		return cmp;
+	c1 = name1[len];
+	c2 = name2[len];
+	if (!c1 && S_ISDIR(mode1))
+		c1 = '/';
+	if (!c2 && S_ISDIR(mode2))
+		c2 = '/';
+	return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
+}
+
 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
 {
 	int len1 = flags1 & CE_NAMEMASK;
@@ -74,7 +132,7 @@ int cache_name_pos(const char *name, int namelen)
 	while (last > first) {
 		int next = (last + first) >> 1;
 		struct cache_entry *ce = active_cache[next];
-		int cmp = cache_name_compare(name, namelen, ce->name, htons(ce->ce_flags));
+		int cmp = cache_name_compare(name, namelen, ce->name, ntohs(ce->ce_flags));
 		if (!cmp)
 			return next;
 		if (cmp < 0) {
@@ -87,8 +145,9 @@ int cache_name_pos(const char *name, int namelen)
 }
 
 /* Remove entry, return true if there are more entries to go.. */
-int remove_entry_at(int pos)
+int remove_cache_entry_at(int pos)
 {
+	active_cache_changed = 1;
 	active_nr--;
 	if (pos >= active_nr)
 		return 0;
@@ -102,24 +161,129 @@ int remove_file_from_cache(char *path)
 	if (pos < 0)
 		pos = -pos-1;
 	while (pos < active_nr && !strcmp(active_cache[pos]->name, path))
-		remove_entry_at(pos);
+		remove_cache_entry_at(pos);
 	return 0;
 }
 
-int same_name(struct cache_entry *a, struct cache_entry *b)
+int ce_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;
 
-	pos = cache_name_pos(ce->name, htons(ce->ce_flags));
+	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, '/');
+		int len;
+		if (!ep)
+			break;
+		*ep = 0;    /* first cut it at slash */
+		len = ep - pathbuf;
+		pos = cache_name_pos(pathbuf,
+				     ntohs(create_ce_flags(len, 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_cache_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,
+			     ntohs(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_cache_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, ntohs(ce->ce_flags));
 
 	/* existing match? Just replace it */
 	if (pos >= 0) {
+		active_cache_changed = 1;
 		active_cache[pos] = ce;
 		return 0;
 	}
@@ -130,9 +294,9 @@ int add_cache_entry(struct cache_entry *ce, int ok_to_add)
 	 * will always replace all non-merged entries..
 	 */
 	if (pos < active_nr && ce_stage(ce) == 0) {
-		while (same_name(active_cache[pos], ce)) {
+		while (ce_same_name(active_cache[pos], ce)) {
 			ok_to_add = 1;
-			if (!remove_entry_at(pos))
+			if (!remove_cache_entry_at(pos))
 				break;
 		}
 	}
@@ -140,6 +304,13 @@ 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, ntohs(ce->ce_flags));
+		pos = -pos-1;
+	}
+
 	/* Make sure the array is big enough .. */
 	if (active_nr == active_alloc) {
 		active_alloc = alloc_nr(active_alloc);
@@ -151,6 +322,7 @@ 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;
 }
 
@@ -183,11 +355,6 @@ 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(get_index_file(), O_RDONLY);
 	if (fd < 0)
 		return (errno == ENOENT) ? 0 : error("open failed");
@@ -227,7 +394,7 @@ unmap:
 }
 
 #define WRITE_BUFFER_SIZE 8192
-static char write_buffer[WRITE_BUFFER_SIZE];
+static unsigned 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)
@@ -273,11 +440,15 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
 {
 	SHA_CTX c;
 	struct cache_header hdr;
-	int i;
+	int i, removed;
+
+	for (i = removed = 0; i < entries; i++)
+		if (!cache[i]->ce_mode)
+			removed++;
 
 	hdr.hdr_signature = htonl(CACHE_SIGNATURE);
 	hdr.hdr_version = htonl(2);
-	hdr.hdr_entries = htonl(entries);
+	hdr.hdr_entries = htonl(entries - removed);
 
 	SHA1_Init(&c);
 	if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
@@ -285,6 +456,8 @@ int write_cache(int newfd, struct cache_entry **cache, int entries)
 
 	for (i = 0; i < entries; i++) {
 		struct cache_entry *ce = cache[i];
+		if (!ce->ce_mode)
+			continue;
 		if (ce_write(&c, newfd, ce, ce_size(ce)) < 0)
 			return -1;
 	}