Cleaned up memory allocation for object_entry structs.

Although its easy to ask the user to tell us how many objects they
will need, its probably better to dynamically grow the object table
in large units.  But if the user can give us a hint as to roughly
how many objects then we can still use it during startup.

Also stopped printing the SHA1 strings to stdout as no user is
currently making use of that facility.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

fast-import.c

@@ -6,59 +6,64 @@
 #include "pack.h"
 #include "csum-file.h"
 
+struct object_entry
+{
+	struct object_entry *next;
+	unsigned long offset;
+	unsigned char sha1[20];
+};
+
+struct object_entry_block
+{
+	struct object_entry_block *next_block;
+	struct object_entry *next_free;
+	struct object_entry *end;
+	struct object_entry entries[0];
+};
+
 static int max_depth = 10;
+static unsigned long alloc_count;
 static unsigned long object_count;
 static unsigned long duplicate_count;
 static unsigned long packoff;
-static unsigned long overflow_count;
 static int packfd;
 static int current_depth;
 static void *lastdat;
 static unsigned long lastdatlen;
 static unsigned char lastsha1[20];
 static unsigned char packsha1[20];
+struct object_entry *object_table[1 << 16];
+struct object_entry_block *blocks;
 
-struct object_entry
+static void alloc_objects(int cnt)
 {
-	struct object_entry *next;
-	unsigned long offset;
-	unsigned char sha1[20];
-};
+	struct object_entry_block *b;
+
+	b = xmalloc(sizeof(struct object_entry_block)
+		+ cnt * sizeof(struct object_entry));
+	b->next_block = blocks;
+	b->next_free = b->entries;
+	b->end = b->entries + cnt;
+	blocks = b;
+	alloc_count += cnt;
+}
 
-struct overflow_object_entry
+static struct object_entry* new_object(unsigned char *sha1)
 {
-	struct overflow_object_entry *next;
-	struct object_entry oe;
-};
+	struct object_entry *e;
 
-struct object_entry *pool_start;
-struct object_entry *pool_next;
-struct object_entry *pool_end;
-struct overflow_object_entry *overflow;
-struct object_entry *table[1 << 16];
+	if (blocks->next_free == blocks->end)
+		alloc_objects(1000);
 
-static struct object_entry* new_object(unsigned char *sha1)
-{
-	if (pool_next != pool_end) {
-		struct object_entry *e = pool_next++;
-		memcpy(e->sha1, sha1, sizeof(e->sha1));
-		return e;
-	} else {
-		struct overflow_object_entry *e;
-
-		e = xmalloc(sizeof(struct overflow_object_entry));
-		e->next = overflow;
-		memcpy(e->oe.sha1, sha1, sizeof(e->oe.sha1));
-		overflow = e;
-		overflow_count++;
-		return &e->oe;
-	}
+	e = blocks->next_free++;
+	memcpy(e->sha1, sha1, sizeof(e->sha1));
+	return e;
 }
 
 static struct object_entry* insert_object(unsigned char *sha1)
 {
 	unsigned int h = sha1[0] << 8 | sha1[1];
-	struct object_entry *e = table[h];
+	struct object_entry *e = object_table[h];
 	struct object_entry *p = 0;
 
 	while (e) {
@@ -74,7 +79,7 @@ static struct object_entry* insert_object(unsigned char *sha1)
 	if (p)
 		p->next = e;
 	else
-		table[h] = e;
+		object_table[h] = e;
 	return e;
 }
 
@@ -246,17 +251,16 @@ static void write_index(const char *idx_name)
 	struct sha1file *f;
 	struct object_entry **idx, **c, **last;
 	struct object_entry *e;
-	struct overflow_object_entry *o;
+	struct object_entry_block *o;
 	unsigned int array[256];
 	int i;
 
 	/* Build the sorted table of object IDs. */
 	idx = xmalloc(object_count * sizeof(struct object_entry*));
 	c = idx;
-	for (e = pool_start; e != pool_next; e++)
-		*c++ = e;
-	for (o = overflow; o; o = o->next)
-		*c++ = &o->oe;
+	for (o = blocks; o; o = o->next_block)
+		for (e = o->entries; e != o->next_free; e++)
+			*c++ = e;
 	last = idx + object_count;
 	qsort(idx, object_count, sizeof(struct object_entry*), oecmp);
 
@@ -297,14 +301,11 @@ int main(int argc, const char **argv)
 	idx_name = xmalloc(strlen(base_name) + 5);
 	sprintf(idx_name, "%s.idx", base_name);
 
-	packfd = open(pack_name, O_RDWR|O_CREAT|O_TRUNC, 0666);
+	packfd = open(pack_name, O_RDWR|O_CREAT|O_EXCL, 0666);
 	if (packfd < 0)
 		die("Can't create pack file %s: %s", pack_name, strerror(errno));
 
-	pool_start = xmalloc(est_obj_cnt * sizeof(struct object_entry));
-	pool_next = pool_start;
-	pool_end = pool_start + est_obj_cnt;
-
+	alloc_objects(est_obj_cnt);
 	init_pack_header();
 	for (;;) {
 		unsigned long datlen;
@@ -334,8 +335,6 @@ int main(int argc, const char **argv)
 			e->offset = packoff;
 			write_blob(dat, datlen);
 			object_count++;
-			printf("%s\n", sha1_to_hex(sha1));
-			fflush(stdout);
 
 			if (lastdat)
 				free(lastdat);
@@ -351,8 +350,8 @@ int main(int argc, const char **argv)
 	close(packfd);
 	write_index(idx_name);
 
-	fprintf(stderr, "%lu objects, %lu duplicates, %lu pool overflow\n",
-		object_count, duplicate_count, overflow_count);
+	fprintf(stderr, "%lu objects, %lu duplicates, %lu allocated (%lu overflow)\n",
+		object_count, duplicate_count, alloc_count, alloc_count - est_obj_cnt);
 
 	return 0;
 }