Make fiel checkout function available to the git library

The merge stuff will want it soon, and we don't want to
duplicate all the work..

4 files changed, 192 insertions, 174 deletions

diff --git a/Makefile b/Makefile
index fff5a6a4bc..d0f1cfa36c 100644
--- a/Makefile
+++ b/Makefile
@@ -40,7 +40,7 @@ install: $(PROG) $(SCRIPTS)
 	$(INSTALL) $(PROG) $(SCRIPTS) $(dest)$(bin)
 
 LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o \
-	 tag.o delta.o date.o index.o diff-delta.o patch-delta.o
+	 tag.o delta.o date.o index.o diff-delta.o patch-delta.o entry.o
 LIB_FILE=libgit.a
 LIB_H=cache.h object.h blob.h tree.h commit.h tag.h delta.h
 
diff --git a/cache.h b/cache.h
index 481f7c7870..7cb5b554b3 100644
--- a/cache.h
+++ b/cache.h
@@ -214,4 +214,15 @@ static inline void *xcalloc(size_t nmemb, size_t size)
 	return ret;
 }
 
+struct checkout {
+	const char *base_dir;
+	int base_dir_len;
+	unsigned force:1,
+		 quiet:1,
+		 not_new:1,
+		 refresh_cache:1;
+};
+
+extern int checkout_entry(struct cache_entry *ce, struct checkout *state);
+
 #endif /* CACHE_H */
diff --git a/checkout-cache.c b/checkout-cache.c
index 9d09c39ee0..82ddbe412a 100644
--- a/checkout-cache.c
+++ b/checkout-cache.c
@@ -32,175 +32,22 @@
  * of "-a" causing problems (not possible in the above example,
  * but get used to it in scripting!).
  */
-#include <sys/types.h>
-#include <dirent.h>
 #include "cache.h"
 
-static int force = 0, quiet = 0, not_new = 0, refresh_cache = 0;
-static const char *base_dir = "";
-static int base_dir_len = 0;
-
-static void create_directories(const char *path)
-{
-	int len = strlen(path);
-	char *buf = xmalloc(len + 1);
-	const char *slash = path;
-
-	while ((slash = strchr(slash+1, '/')) != NULL) {
-		len = slash - path;
-		memcpy(buf, path, len);
-		buf[len] = 0;
-		if (mkdir(buf, 0755)) {
-			if (errno == EEXIST) {
-				struct stat st;
-				if (len > base_dir_len && force && !unlink(buf) && !mkdir(buf, 0755))
-					continue;
-				if (!stat(buf, &st) && S_ISDIR(st.st_mode))
-					continue; /* ok */
-			}
-			die("cannot create directory at %s", buf);
-		}
-	}
-	free(buf);
-}
-
-static void remove_subtree(const char *path)
-{
-	DIR *dir = opendir(path);
-	struct dirent *de;
-	char pathbuf[PATH_MAX];
-	char *name;
-	
-	if (!dir)
-		die("cannot opendir %s", path);
-	strcpy(pathbuf, path);
-	name = pathbuf + strlen(path);
-	*name++ = '/';
-	while ((de = readdir(dir)) != NULL) {
-		struct stat st;
-		if ((de->d_name[0] == '.') &&
-		    ((de->d_name[1] == 0) ||
-		     ((de->d_name[1] == '.') && de->d_name[2] == 0)))
-			continue;
-		strcpy(name, de->d_name);
-		if (lstat(pathbuf, &st))
-			die("cannot lstat %s", pathbuf);
-		if (S_ISDIR(st.st_mode))
-			remove_subtree(pathbuf);
-		else if (unlink(pathbuf))
-			die("cannot unlink %s", pathbuf);
-	}
-	closedir(dir);
-	if (rmdir(path))
-		die("cannot rmdir %s", path);
-}
-
-static int create_file(const char *path, unsigned int mode)
-{
-	int fd;
-
-	mode = (mode & 0100) ? 0777 : 0666;
-	create_directories(path);
-	fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
-	if (fd < 0) {
-		if (errno == EISDIR && force) {
-			remove_subtree(path);
-			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
-		}
-	}
-	return fd;
-}
-
-static int write_entry(struct cache_entry *ce, const char *path)
-{
-	int fd;
-	void *new;
-	unsigned long size;
-	long wrote;
-	char type[20];
-	char target[1024];
-
-	new = read_sha1_file(ce->sha1, type, &size);
-	if (!new || strcmp(type, "blob")) {
-		if (new)
-			free(new);
-		return error("git-checkout-cache: unable to read sha1 file of %s (%s)",
-			path, sha1_to_hex(ce->sha1));
-	}
-	switch (ntohl(ce->ce_mode) & S_IFMT) {
-	case S_IFREG:
-		fd = create_file(path, ntohl(ce->ce_mode));
-		if (fd < 0) {
-			free(new);
-			return error("git-checkout-cache: unable to create file %s (%s)",
-				path, strerror(errno));
-		}
-		wrote = write(fd, new, size);
-		close(fd);
-		free(new);
-		if (wrote != size)
-			return error("git-checkout-cache: unable to write file %s", path);
-		break;
-	case S_IFLNK:
-		memcpy(target, new, size);
-		target[size] = '\0';
-		create_directories(path);
-		if (symlink(target, path)) {
-			free(new);
-			return error("git-checkout-cache: unable to create symlink %s (%s)",
-				path, strerror(errno));
-		}
-		free(new);
-		break;
-	default:
-		free(new);
-		return error("git-checkout-cache: unknown file mode for %s", path);
-	}
-
-	if (refresh_cache) {
-		struct stat st;
-		lstat(ce->name, &st);
-		fill_stat_cache_info(ce, &st);
-	}
-	return 0;
-}
-
-static int checkout_entry(struct cache_entry *ce)
-{
-	struct stat st;
-	static char path[MAXPATHLEN+1];
-	int len = base_dir_len;
-
-	memcpy(path, base_dir, len);
-	strcpy(path + len, ce->name);
-
-	if (!lstat(path, &st)) {
-		unsigned changed = ce_match_stat(ce, &st);
-		if (!changed)
-			return 0;
-		if (!force) {
-			if (!quiet)
-				fprintf(stderr, "git-checkout-cache: %s already exists\n", path);
-			return 0;
-		}
-
-		/*
-		 * We unlink the old file, to get the new one with the
-		 * right permissions (including umask, which is nasty
-		 * to emulate by hand - much easier to let the system
-		 * just do the right thing)
-		 */
-		unlink(path);
-	} else if (not_new) 
-		return 0;
-	return write_entry(ce, path);
-}
+static struct checkout state = {
+	.base_dir = "",
+	.base_dir_len = 0,
+	.force = 0,
+	.quiet = 0,
+	.not_new = 0,
+	.refresh_cache = 0,
+};
 
 static int checkout_file(const char *name)
 {
 	int pos = cache_name_pos(name, strlen(name));
 	if (pos < 0) {
-		if (!quiet) {
+		if (!state.quiet) {
 			pos = -pos - 1;
 			fprintf(stderr,
 				"git-checkout-cache: %s is %s.\n",
@@ -211,7 +58,7 @@ static int checkout_file(const char *name)
 		}
 		return -1;
 	}
-	return checkout_entry(active_cache[pos]);
+	return checkout_entry(active_cache[pos], &state);
 }
 
 static int checkout_all(void)
@@ -222,7 +69,7 @@ static int checkout_all(void)
 		struct cache_entry *ce = active_cache[i];
 		if (ce_stage(ce))
 			continue;
-		if (checkout_entry(ce) < 0)
+		if (checkout_entry(ce, &state) < 0)
 			return -1;
 	}
 	return 0;
@@ -250,19 +97,19 @@ int main(int argc, char **argv)
 				continue;
 			}
 			if (!strcmp(arg, "-f")) {
-				force = 1;
+				state.force = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-q")) {
-				quiet = 1;
+				state.quiet = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-n")) {
-				not_new = 1;
+				state.not_new = 1;
 				continue;
 			}
 			if (!strcmp(arg, "-u")) {
-				refresh_cache = 1;
+				state.refresh_cache = 1;
 				if (newfd < 0)
 					newfd = hold_index_file_for_update
 						(&cache_file,
@@ -272,20 +119,20 @@ int main(int argc, char **argv)
 				continue;
 			}
 			if (!memcmp(arg, "--prefix=", 9)) {
-				base_dir = arg+9;
-				base_dir_len = strlen(base_dir);
+				state.base_dir = arg+9;
+				state.base_dir_len = strlen(state.base_dir);
 				continue;
 			}
 		}
-		if (base_dir_len) {
+		if (state.base_dir_len) {
 			/* when --prefix is specified we do not
 			 * want to update cache.
 			 */
-			if (refresh_cache) {
+			if (state.refresh_cache) {
 				close(newfd); newfd = -1;
 				rollback_index_file(&cache_file);
 			}
-			refresh_cache = 0;
+			state.refresh_cache = 0;
 		}
 		checkout_file(arg);
 	}
diff --git a/entry.c b/entry.c
new file mode 100644
index 0000000000..d7824c4f61
--- /dev/null
+++ b/entry.c
@@ -0,0 +1,160 @@
+#include <sys/types.h>
+#include <dirent.h>
+#include "cache.h"
+
+static void create_directories(const char *path, struct checkout *state)
+{
+	int len = strlen(path);
+	char *buf = xmalloc(len + 1);
+	const char *slash = path;
+
+	while ((slash = strchr(slash+1, '/')) != NULL) {
+		len = slash - path;
+		memcpy(buf, path, len);
+		buf[len] = 0;
+		if (mkdir(buf, 0755)) {
+			if (errno == EEXIST) {
+				struct stat st;
+				if (len > state->base_dir_len && state->force && !unlink(buf) && !mkdir(buf, 0755))
+					continue;
+				if (!stat(buf, &st) && S_ISDIR(st.st_mode))
+					continue; /* ok */
+			}
+			die("cannot create directory at %s", buf);
+		}
+	}
+	free(buf);
+}
+
+static void remove_subtree(const char *path)
+{
+	DIR *dir = opendir(path);
+	struct dirent *de;
+	char pathbuf[PATH_MAX];
+	char *name;
+	
+	if (!dir)
+		die("cannot opendir %s", path);
+	strcpy(pathbuf, path);
+	name = pathbuf + strlen(path);
+	*name++ = '/';
+	while ((de = readdir(dir)) != NULL) {
+		struct stat st;
+		if ((de->d_name[0] == '.') &&
+		    ((de->d_name[1] == 0) ||
+		     ((de->d_name[1] == '.') && de->d_name[2] == 0)))
+			continue;
+		strcpy(name, de->d_name);
+		if (lstat(pathbuf, &st))
+			die("cannot lstat %s", pathbuf);
+		if (S_ISDIR(st.st_mode))
+			remove_subtree(pathbuf);
+		else if (unlink(pathbuf))
+			die("cannot unlink %s", pathbuf);
+	}
+	closedir(dir);
+	if (rmdir(path))
+		die("cannot rmdir %s", path);
+}
+
+static int create_file(const char *path, unsigned int mode, int force)
+{
+	int fd;
+
+	mode = (mode & 0100) ? 0777 : 0666;
+	fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
+	if (fd < 0) {
+		if (errno == EISDIR && force) {
+			remove_subtree(path);
+			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
+		}
+	}
+	return fd;
+}
+
+static int write_entry(struct cache_entry *ce, const char *path, struct checkout *state)
+{
+	int fd;
+	void *new;
+	unsigned long size;
+	long wrote;
+	char type[20];
+	char target[1024];
+
+	new = read_sha1_file(ce->sha1, type, &size);
+	if (!new || strcmp(type, "blob")) {
+		if (new)
+			free(new);
+		return error("git-checkout-cache: unable to read sha1 file of %s (%s)",
+			path, sha1_to_hex(ce->sha1));
+	}
+	switch (ntohl(ce->ce_mode) & S_IFMT) {
+	case S_IFREG:
+		fd = create_file(path, ntohl(ce->ce_mode), state->force);
+		if (fd < 0) {
+			free(new);
+			return error("git-checkout-cache: unable to create file %s (%s)",
+				path, strerror(errno));
+		}
+		wrote = write(fd, new, size);
+		close(fd);
+		free(new);
+		if (wrote != size)
+			return error("git-checkout-cache: unable to write file %s", path);
+		break;
+	case S_IFLNK:
+		memcpy(target, new, size);
+		target[size] = '\0';
+		if (symlink(target, path)) {
+			free(new);
+			return error("git-checkout-cache: unable to create symlink %s (%s)",
+				path, strerror(errno));
+		}
+		free(new);
+		break;
+	default:
+		free(new);
+		return error("git-checkout-cache: unknown file mode for %s", path);
+	}
+
+	if (state->update) {
+		struct stat st;
+		lstat(ce->name, &st);
+		fill_stat_cache_info(ce, &st);
+	}
+	return 0;
+}
+
+int checkout_entry(struct cache_entry *ce, struct checkout *state)
+{
+	struct stat st;
+	static char path[MAXPATHLEN+1];
+	int len = state->base_dir_len;
+
+	memcpy(path, state->base_dir, len);
+	strcpy(path + len, ce->name);
+
+	if (!lstat(path, &st)) {
+		unsigned changed = ce_match_stat(ce, &st);
+		if (!changed)
+			return 0;
+		if (!state->force) {
+			if (!state->quiet)
+				fprintf(stderr, "git-checkout-cache: %s already exists\n", path);
+			return 0;
+		}
+
+		/*
+		 * We unlink the old file, to get the new one with the
+		 * right permissions (including umask, which is nasty
+		 * to emulate by hand - much easier to let the system
+		 * just do the right thing)
+		 */
+		unlink(path);
+	} else if (state->not_new) 
+		return 0;
+	create_directories(path, state);
+	return write_entry(ce, path, state);
+}
+
+