[0/2] Complete http-pull

@@ -29,9 +29,10 @@
 	install $(PROG) $(SCRIPTS) $(HOME)/bin/
 
 LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o \
-	 tag.o date.o
+	 tag.o date.o refs.o
+
 LIB_FILE=libgit.a
-LIB_H=cache.h object.h blob.h tree.h commit.h tag.h
+LIB_H=cache.h object.h blob.h tree.h commit.h tag.h refs.h
 
 LIB_H += strbuf.h
 LIB_OBJS += strbuf.o

@@ -100,6 +100,11 @@
 
 #define get_object_directory() (getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT)
 
+#define REF_ENVIRONMENT "REF_FILE_DIRECTORY"
+#define DEFAULT_REF_ENVIRONMENT ".git/refs"
+
+#define get_refs_directory() (getenv(REF_ENVIRONMENT) ? : DEFAULT_REF_ENVIRONMENT)
+
 #define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
 #define DEFAULT_INDEX_ENVIRONMENT ".git/index"
 

@@ -38,6 +38,7 @@
 	memcpy(path, sha1_dir, len);
 
 	safe_create_dir(sha1_dir);
+	safe_create_dir(get_refs_directory());
 	for (i = 0; i < 256; i++) {
 		sprintf(path+len, "/%02x", i);
 		safe_create_dir(path);

@@ -0,0 +1,139 @@
+#include "refs.h"
+#include "cache.h"
+
+#include <errno.h>
+
+static char *split_ref_file_name(const char *dir, const char *name)
+{
+	char *base = get_refs_directory();
+	int baselen = strlen(base);
+	int dirlen = strlen(dir);
+	int namelen = strlen(name);
+	char *ret;
+	if (dir[0] == '.')
+		return NULL;
+	if (strchr(dir, '/'))
+		return NULL;
+	if (strchr(name, '/'))
+		return NULL;
+	ret = xmalloc(baselen + 3 + dirlen + namelen);
+	strcpy(ret, base);
+	ret[baselen] = '/';
+	strcpy(ret + baselen + 1, dir);
+	ret[baselen + 1 + dirlen] = '/';
+	strcpy(ret + baselen + 2 + dirlen, name);
+	ret[baselen + 2 + dirlen + namelen] = '\0';
+	return ret;
+}
+
+static char *ref_file_name(const char *ref)
+{
+	char *base = get_refs_directory();
+	int baselen = strlen(base);
+	int reflen = strlen(ref);
+	char *ret;
+	char *check;
+	if (ref[0] == '.')
+		return NULL;
+	check = strchr(ref, '/');
+	if (!check)
+		return NULL;
+	if (strchr(check + 1, '/'))
+		return NULL;
+	ret = xmalloc(baselen + 2 + reflen);
+	strcpy(ret, base);
+	ret[baselen] = '/';
+	strcpy(ret + baselen + 1, ref);
+	ret[baselen + 1 + reflen] = '\0';
+	return ret;
+}
+
+static int read_ref_file(char *filename, unsigned char *sha1) {
+	int fd = open(filename, O_RDONLY);
+	char hex[41];
+	if (fd < 0) {
+		return error("Couldn't open %s\n", filename);
+	}
+	if ((read(fd, hex, 41) < 41) ||
+	    (hex[40] != '\n') ||
+	    get_sha1_hex(hex, sha1)) {
+		error("Couldn't read a hash from %s\n", filename);
+		close(fd);
+		return -1;
+	}
+	close(fd);
+	return 0;
+}
+
+int get_split_ref_sha1(const char *dir, const char *name, unsigned char *sha1)
+{
+	char *filename = split_ref_file_name(dir, name);
+	int retval;
+	if (!filename)
+		return -1;
+	retval = read_ref_file(filename, sha1);
+	free(filename);
+	return retval;
+}
+
+int get_ref_sha1(const char *ref, unsigned char *sha1)
+{
+	char *filename = ref_file_name(ref);
+	int retval;
+	if (!filename)
+		return -1;
+	retval = read_ref_file(filename, sha1);
+	free(filename);
+	return retval;
+}
+
+int write_split_ref_sha1(const char *dir, const char *name,
+			 unsigned char *sha1)
+{
+	char *filename = split_ref_file_name(dir, name);
+	char *hex = sha1_to_hex(sha1);
+	char term = '\n';
+	int fd;
+	if (!filename)
+		return -1;
+	unlink(filename);
+	fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	if (fd < 0 && errno == ENOENT) {
+		char *dirname = split_ref_file_name(dir, "");
+		mkdir(dirname, 0755);
+		free(dirname);
+		fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	}
+	if (fd < 0) {
+		error("Couldn't open for writing %s: %s\n", filename,
+		      strerror(errno));
+		free(filename);
+		return -1;
+	}
+	if (write(fd, hex, 40) < 40 ||
+	    write(fd, &term, 1) < 1) {
+		error("Couldn't write %s\n", filename);
+		free(filename);
+		close(fd);
+		return -1;
+	}
+	close(fd);
+	return 0;
+	
+}
+
+int split_ref(char **dir, char **name, const char *ref)
+{
+	char *middle = strchr(ref, '/');
+	if (ref[0] == '.')
+		return -1;
+	if (!middle)
+		return -1;
+	if (strchr(middle + 1, '/'))
+		return -1;
+	*dir = xmalloc(middle - ref + 1);
+	*name = strdup(middle + 1);
+	(*dir)[middle - ref] = '\0';
+	memcpy(*dir, ref, middle - ref);
+	return 0;
+}

@@ -0,0 +1,20 @@
+#ifndef REFS_H
+#define REFS_H
+
+/** Reads the refs file specified into sha1 **/
+extern int get_split_ref_sha1(const char *dir, const char *name,
+			      unsigned char *sha1);
+
+/** Reads the refs file specified into sha1 **/
+extern int get_ref_sha1(const char *ref, unsigned char *sha1);
+
+/** Writes sha1 into the refs file specified **/
+extern int write_split_ref_sha1(const char *dir, const char *name, 
+				unsigned char *sha1);
+
+/** Sets dir and name to the directory and name parts of ref, in new
+ * storage. 
+ **/
+extern int split_ref(char **dir, char **name, const char *ref);
+
+#endif /* REFS_H */

@@ -7,6 +7,8 @@
 #include <errno.h>
 #include <stdio.h>
 
+#include "refs.h"
+
 #include "pull.h"
 
 #include <curl/curl.h>

@@ -45,6 +47,23 @@
 	return size;
 }
 
+struct buffer
+{
+	size_t posn;
+	size_t size;
+	void *buffer;
+};
+
+static size_t fwrite_buffer(void *ptr, size_t eltsize, size_t nmemb,
+			    struct buffer *buffer) {
+	size_t size = eltsize * nmemb;
+	if (size > buffer->size - buffer->posn)
+		size = buffer->size - buffer->posn;
+	memcpy(buffer->buffer + buffer->posn, ptr, size);
+	buffer->posn += size;
+	return size;
+}
+
 int fetch(unsigned char *sha1)
 {
 	char *hex = sha1_to_hex(sha1);

@@ -103,6 +122,40 @@
 	return 0;
 }
 
+int fetch_ref(char *dir, char *name, unsigned char *sha1)
+{
+	char *url, *posn;
+	char hex[42];
+	struct buffer buffer;
+	buffer.size = 41;
+	buffer.posn = 0;
+	buffer.buffer = hex;
+	hex[41] = '\0';
+	
+	curl_easy_setopt(curl, CURLOPT_FILE, &buffer);
+	curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, fwrite_buffer);
+
+	url = xmalloc(strlen(base) + 7 + strlen(dir) + strlen(name));
+	strcpy(url, base);
+	posn = url + strlen(base);
+	strcpy(posn, "refs/");
+	posn += 5;
+	strcpy(posn, dir);
+	posn += strlen(dir);
+	*(posn++) = '/';
+	strcpy(posn, name);
+
+	curl_easy_setopt(curl, CURLOPT_URL, url);
+
+	if (curl_easy_perform(curl))
+		return error("Couldn't get %s for %s/%s\n", url,
+			     dir, name);
+
+	hex[40] = '\0';
+	get_sha1_hex(hex, sha1);
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	char *commit_id;

@@ -118,6 +171,10 @@
 			get_all = 1;
 			get_tree = 1;
 			get_history = 1;
+		} else if (argv[arg][1] == 'w') {
+			char *write_ref = argv[arg + 1];
+			split_ref(&write_ref_dir, &write_ref_name, write_ref);
+			arg++;
 		}
 		arg++;
 	}

@@ -3,6 +3,12 @@
 #include "cache.h"
 #include "commit.h"
 #include "tree.h"
+#include "tag.h"
+
+#include "refs.h"
+
+char *write_ref_dir = NULL;
+char *write_ref_name = NULL;
 
 int get_tree = 0;
 int get_history = 0;

@@ -61,15 +67,53 @@
 	return 0;
 }
 
+static int process_tag(unsigned char *sha1)
+{
+	return 0;
+}
+
+static int process_unknown(unsigned char *sha1)
+{
+	struct object *obj;
+	if (fetch(sha1))
+		return -1;
+	obj = parse_object(sha1);
+	if (obj->type == commit_type)
+		return process_commit(sha1);
+	else if (obj->type == tag_type)
+		return process_tag(sha1);
+	return error("Cannot pull a %s object", obj->type);
+}
+
+static int interpret_target(char *target, unsigned char *sha1)
+{
+	char *dir, *name;
+	if (!get_sha1_hex(target, sha1))
+		return 0;
+	if (!split_ref(&dir, &name, target)) {
+		if (!fetch_ref(dir, name, sha1)) {
+			return 0;
+		}
+	}
+	return -1;
+}
+
 int pull(char *target)
 {
 	int retval;
 	unsigned char sha1[20];
-	retval = get_sha1_hex(target, sha1);
+	retval = interpret_target(target, sha1);
+	if (retval) {
+		return error("Could not interpret %s as something to pull",
+			     target);
+	}
+	retval = fetch(sha1);
 	if (retval)
 		return retval;
-	retval = fetch(sha1);
+	retval = process_unknown(sha1);
 	if (retval)
 		return retval;
-	return process_commit(sha1);
+	if (write_ref_dir && write_ref_name)
+		write_split_ref_sha1(write_ref_dir, write_ref_name, sha1);
+	return 0;
 }

@@ -4,6 +4,12 @@
 /** To be provided by the particular implementation. **/
 extern int fetch(unsigned char *sha1);
 
+extern int fetch_ref(char *dir, char *name, unsigned char *sha1);
+
+/** Ref filename to write target to. **/
+extern char *write_ref_dir;
+extern char *write_ref_name;
+
 /** Set to fetch the target tree. */
 extern int get_tree;
 

@@ -20,6 +20,11 @@
 	return write_sha1_from_fd(sha1, fd_in);
 }
 
+int fetch_ref(char *name, char *dir, unsigned char *sha1)
+{
+	return -1;
+}
+
 int main(int argc, char **argv)
 {
 	char *commit_id;