Merge the new object model thing from Daniel Barkalow

This was a real git merge with conflicts. I'll commit the scripts I used
to do the merge next.

Not pretty, but it's half-way functional.

Author: Linus Torvalds

Makefile

@@ -43,17 +43,17 @@ commit-tree: commit-tree.o read-cache.o
 cat-file: cat-file.o read-cache.o
 	$(CC) $(CFLAGS) -o cat-file cat-file.o read-cache.o $(LIBS)
 
-fsck-cache: fsck-cache.o read-cache.o
-	$(CC) $(CFLAGS) -o fsck-cache fsck-cache.o read-cache.o $(LIBS)
+fsck-cache: fsck-cache.o read-cache.o object.o commit.o tree.o blob.o
+	$(CC) $(CFLAGS) -o fsck-cache fsck-cache.o read-cache.o object.o commit.o tree.o blob.o $(LIBS)
 
 checkout-cache: checkout-cache.o read-cache.o
 	$(CC) $(CFLAGS) -o checkout-cache checkout-cache.o read-cache.o $(LIBS)
 
 diff-tree: diff-tree.o read-cache.o
 	$(CC) $(CFLAGS) -o diff-tree diff-tree.o read-cache.o $(LIBS)
 
-rev-tree: rev-tree.o read-cache.o
-	$(CC) $(CFLAGS) -o rev-tree rev-tree.o read-cache.o $(LIBS)
+rev-tree: rev-tree.o read-cache.o object.o commit.o tree.o blob.o
+	$(CC) $(CFLAGS) -o rev-tree rev-tree.o read-cache.o object.o commit.o tree.o blob.o $(LIBS)
 
 show-files: show-files.o read-cache.o
 	$(CC) $(CFLAGS) -o show-files show-files.o read-cache.o $(LIBS)
@@ -64,8 +64,8 @@ check-files: check-files.o read-cache.o
 ls-tree: ls-tree.o read-cache.o
 	$(CC) $(CFLAGS) -o ls-tree ls-tree.o read-cache.o $(LIBS)
 
-merge-base: merge-base.o read-cache.o
-	$(CC) $(CFLAGS) -o merge-base merge-base.o read-cache.o $(LIBS)
+merge-base: merge-base.o read-cache.o object.o commit.o tree.o blob.o
+	$(CC) $(CFLAGS) -o merge-base merge-base.o read-cache.o object.o commit.o tree.o blob.o $(LIBS)
 
 merge-cache: merge-cache.o read-cache.o
 	$(CC) $(CFLAGS) -o merge-cache merge-cache.o read-cache.o $(LIBS)

blob.c

@@ -0,0 +1,24 @@
+#include "blob.h"
+#include "cache.h"
+#include <stdlib.h>
+
+const char *blob_type = "blob";
+
+struct blob *lookup_blob(unsigned char *sha1)
+{
+	struct object *obj = lookup_object(sha1);
+	if (!obj) {
+		struct blob *ret = malloc(sizeof(struct blob));
+		memset(ret, 0, sizeof(struct blob));
+		created_object(sha1, &ret->object);
+		ret->object.type = blob_type;
+		ret->object.parsed = 1;
+		return ret;
+	}
+	if (obj->parsed && obj->type != blob_type) {
+		error("Object %s is a %s, not a blob", 
+		      sha1_to_hex(sha1), obj->type);
+		return NULL;
+	}
+	return (struct blob *) obj;
+}

blob.h

@@ -0,0 +1,14 @@
+#ifndef BLOB_H
+#define BLOB_H
+
+#include "object.h"
+
+extern const char *blob_type;
+
+struct blob {
+	struct object object;
+};
+
+struct blob *lookup_blob(unsigned char *sha1);
+
+#endif /* BLOB_H */

commit.c

@@ -0,0 +1,85 @@
+#include "commit.h"
+#include "cache.h"
+#include <string.h>
+
+const char *commit_type = "commit";
+
+struct commit *lookup_commit(unsigned char *sha1)
+{
+	struct object *obj = lookup_object(sha1);
+	if (!obj) {
+		struct commit *ret = malloc(sizeof(struct commit));
+		memset(ret, 0, sizeof(struct commit));
+		created_object(sha1, &ret->object);
+		return ret;
+	}
+	if (obj->parsed && obj->type != commit_type) {
+		error("Object %s is a %s, not a commit", 
+		      sha1_to_hex(sha1), obj->type);
+		return NULL;
+	}
+	return (struct commit *) obj;
+}
+
+static unsigned long parse_commit_date(const char *buf)
+{
+	unsigned long date;
+
+	if (memcmp(buf, "author", 6))
+		return 0;
+	while (*buf++ != '\n')
+		/* nada */;
+	if (memcmp(buf, "committer", 9))
+		return 0;
+	while (*buf++ != '>')
+		/* nada */;
+	date = strtoul(buf, NULL, 10);
+	if (date == ULONG_MAX)
+		date = 0;
+	return date;
+}
+
+int parse_commit(struct commit *item)
+{
+	char type[20];
+	void * buffer, *bufptr;
+	unsigned long size;
+	unsigned char parent[20];
+	if (item->object.parsed)
+		return 0;
+	item->object.parsed = 1;
+	buffer = bufptr = read_sha1_file(item->object.sha1, type, &size);
+	if (!buffer)
+		return error("Could not read %s",
+			     sha1_to_hex(item->object.sha1));
+	if (strcmp(type, commit_type))
+		return error("Object %s not a commit",
+			     sha1_to_hex(item->object.sha1));
+	item->object.type = commit_type;
+	get_sha1_hex(bufptr + 5, parent);
+	item->tree = lookup_tree(parent);
+	add_ref(&item->object, &item->tree->object);
+	bufptr += 46; /* "tree " + "hex sha1" + "\n" */
+	while (!memcmp(bufptr, "parent ", 7) &&
+	       !get_sha1_hex(bufptr + 7, parent)) {
+		struct commit_list *new_parent = 
+			malloc(sizeof(struct commit_list));
+		new_parent->next = item->parents;
+		new_parent->item = lookup_commit(parent);
+		add_ref(&item->object, &new_parent->item->object);
+		item->parents = new_parent;
+		bufptr += 48;
+	}
+	item->date = parse_commit_date(bufptr);
+	free(buffer);
+	return 0;
+}
+
+void free_commit_list(struct commit_list *list)
+{
+	while (list) {
+		struct commit_list *temp = list;
+		list = temp->next;
+		free(temp);
+	}
+}

commit.h

@@ -0,0 +1,27 @@
+#ifndef COMMIT_H
+#define COMMIT_H
+
+#include "object.h"
+#include "tree.h"
+
+struct commit_list {
+	struct commit *item;
+	struct commit_list *next;
+};
+
+struct commit {
+	struct object object;
+	unsigned long date;
+	struct commit_list *parents;
+	struct tree *tree;
+};
+
+extern const char *commit_type;
+
+struct commit *lookup_commit(unsigned char *sha1);
+
+int parse_commit(struct commit *item);
+
+void free_commit_list(struct commit_list *list);
+
+#endif /* COMMIT_H */

fsck-cache.c

@@ -3,7 +3,11 @@
 #include <sys/types.h>
 #include <dirent.h>
 
-#include "revision.h"
+#include "commit.h"
+#include "tree.h"
+#include "blob.h"
+
+#define REACHABLE 0x0001
 
 static int show_unreachable = 0;
 static unsigned char head_sha1[20];
@@ -13,96 +17,54 @@ static void check_connectivity(void)
 	int i;
 
 	/* Look up all the requirements, warn about missing objects.. */
-	for (i = 0; i < nr_revs; i++) {
-		struct revision *rev = revs[i];
+	for (i = 0; i < nr_objs; i++) {
+		struct object *obj = objs[i];
 
-		if (show_unreachable && !(rev->flags & REACHABLE)) {
-			printf("unreachable %s %s\n", rev->tag, sha1_to_hex(rev->sha1));
+		if (show_unreachable && !(obj->flags & REACHABLE)) {
+			printf("unreachable %s\n", sha1_to_hex(obj->sha1));
 			continue;
 		}
 
-		switch (rev->flags & (SEEN | USED)) {
-		case 0:
-			printf("bad %s %s\n", rev->tag, sha1_to_hex(rev->sha1));
-			break;
-		case USED:
-			printf("missing %s, %s\n", rev->tag, sha1_to_hex(rev->sha1));
-			break;
-		case SEEN:
-			printf("dangling %s %s\n", rev->tag, sha1_to_hex(rev->sha1));
-			break;
+		if (!obj->parsed) {
+			printf("missing %s %s\n", obj->type, 
+			       sha1_to_hex(obj->sha1));
+		}
+		if (!obj->used) {
+			printf("dangling %s %s\n", obj->type, 
+			       sha1_to_hex(obj->sha1));
 		}
 	}
 }
 
-static void mark_needs_sha1(unsigned char *parent, const char *ptag, unsigned char *child, const char *ctag)
-{
-	struct revision * child_rev = add_relationship(lookup_rev(parent, ptag), child, ctag);
-	child_rev->flags |= USED;
-}
-
-static int mark_sha1_seen(unsigned char *sha1, const char *tag)
-{
-	struct revision *rev = lookup_rev(sha1, tag);
-
-	rev->flags |= SEEN;
-	return 0;
-}
-
 static int fsck_tree(unsigned char *sha1, void *data, unsigned long size)
 {
-	int warn_old_tree = 1;
-
-	while (size) {
-		int len = 1+strlen(data);
-		unsigned char *file_sha1 = data + len;
-		char *path = strchr(data, ' ');
-		unsigned int mode;
-		if (size < len + 20 || !path || sscanf(data, "%o", &mode) != 1)
-			return -1;
-
-		/* Warn about trees that don't do the recursive thing.. */
-		if (warn_old_tree && strchr(path, '/')) {
-			fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
-			warn_old_tree = 0;
-		}
-
-		data += len + 20;
-		size -= len + 20;
-		mark_needs_sha1(sha1, "tree", file_sha1, S_ISDIR(mode) ? "tree" : "blob");
+	struct tree *item = lookup_tree(sha1);
+	if (parse_tree(item))
+		return -1;
+	if (item->has_full_path) {
+		fprintf(stderr, "warning: fsck-cache: tree %s "
+			"has full pathnames in it\n", sha1_to_hex(sha1));
 	}
 	return 0;
 }
 
 static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
 {
-	int parents;
-	unsigned char tree_sha1[20];
-	unsigned char parent_sha1[20];
-
-	if (memcmp(data, "tree ", 5))
+	struct commit *commit = lookup_commit(sha1);
+	if (parse_commit(commit))
 		return -1;
-	if (get_sha1_hex(data + 5, tree_sha1) < 0)
+	if (!commit->tree)
 		return -1;
-	mark_needs_sha1(sha1, "commit", tree_sha1, "tree");
-	data += 5 + 40 + 1;	/* "tree " + <hex sha1> + '\n' */
-	parents = 0;
-	while (!memcmp(data, "parent ", 7)) {
-		if (get_sha1_hex(data + 7, parent_sha1) < 0)
-			return -1;
-		mark_needs_sha1(sha1, "commit", parent_sha1, "commit");
-		data += 7 + 40 + 1; 	/* "parent " + <hex sha1> + '\n' */
-		parents++;
-	}
-	if (!parents)
+	if (!commit->parents)
 		printf("root %s\n", sha1_to_hex(sha1));
 	return 0;
 }
 
-static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
+static int fsck_entry(unsigned char *sha1, char *tag, void *data, 
+		      unsigned long size)
 {
 	if (!strcmp(tag, "blob")) {
-		/* Nothing to check */;
+		lookup_blob(sha1); /* Nothing to check; but notice it. */
 	} else if (!strcmp(tag, "tree")) {
 		if (fsck_tree(sha1, data, size) < 0)
 			return -1;
@@ -111,7 +73,7 @@ static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long
 			return -1;
 	} else
 		return -1;
-	return mark_sha1_seen(sha1, tag);
+	return 0;
 }
 
 static int fsck_name(char *hex)
@@ -125,7 +87,8 @@ static int fsck_name(char *hex)
 			unsigned long size;
 			void *buffer = NULL;
 			if (!check_sha1_signature(sha1, map, mapsize))
-				buffer = unpack_sha1_file(map, mapsize, type, &size);
+				buffer = unpack_sha1_file(map, mapsize, type,
+							  &size);
 			munmap(map, mapsize);
 			if (buffer && !fsck_entry(sha1, type, buffer, size))
 				return 0;
@@ -186,7 +149,9 @@ int main(int argc, char **argv)
 			continue;
 		}
 		if (!get_sha1_hex(argv[i], head_sha1)) {
-			mark_reachable(lookup_rev(head_sha1, "commit"), REACHABLE);
+			struct object *obj = &lookup_commit(head_sha1)->object;
+			obj->used = 1;
+			mark_reachable(obj, REACHABLE);
 			heads++;
 			continue;
 		}