Initial revision of "git", the information manager from hell

1 files changed, 66 insertions, 0 deletions

diff --git a/write-tree.c b/write-tree.c
new file mode 100644
index 0000000000..921f981353
--- /dev/null
+++ b/write-tree.c
@@ -0,0 +1,66 @@
+#include "cache.h"
+
+static int check_valid_sha1(unsigned char *sha1)
+{
+	char *filename = sha1_file_name(sha1);
+	int ret;
+
+	/* If we were anal, we'd check that the sha1 of the contents actually matches */
+	ret = access(filename, R_OK);
+	if (ret)
+		perror(filename);
+	return ret;
+}
+
+static int prepend_integer(char *buffer, unsigned val, int i)
+{
+	buffer[--i] = '\0';
+	do {
+		buffer[--i] = '0' + (val % 10);
+		val /= 10;
+	} while (val);
+	return i;
+}
+
+#define ORIG_OFFSET (40)	/* Enough space to add the header of "tree <size>\0" */
+
+int main(int argc, char **argv)
+{
+	unsigned long size, offset, val;
+	int i, entries = read_cache();
+	char *buffer;
+
+	if (entries <= 0) {
+		fprintf(stderr, "No file-cache to create a tree of\n");
+		exit(1);
+	}
+
+	/* Guess at an initial size */
+	size = entries * 40 + 400;
+	buffer = malloc(size);
+	offset = ORIG_OFFSET;
+
+	for (i = 0; i < entries; i++) {
+		struct cache_entry *ce = active_cache[i];
+		if (check_valid_sha1(ce->sha1) < 0)
+			exit(1);
+		if (offset + ce->namelen + 60 > size) {
+			size = alloc_nr(offset + ce->namelen + 60);
+			buffer = realloc(buffer, size);
+		}
+		offset += sprintf(buffer + offset, "%o %s", ce->st_mode, ce->name);
+		buffer[offset++] = 0;
+		memcpy(buffer + offset, ce->sha1, 20);
+		offset += 20;
+	}
+
+	i = prepend_integer(buffer, offset - ORIG_OFFSET, ORIG_OFFSET);
+	i -= 5;
+	memcpy(buffer+i, "tree ", 5);
+
+	buffer += i;
+	offset -= i;
+
+	write_sha1_file(buffer, offset);
+	return 0;
+}