From: Stefan Sperling <stsp@stsp.name>
Subject: add checksumming support to got_deflate_to_file
To: gameoftrees@openbsd.org
Date: Thu, 20 May 2021 12:00:35 +0200

This will eventually be used by 'gotadmin pack'

ok?

diff 9069347b693ed2803ca224d77823b2e4e2f2e4e5 /home/stsp/src/got
blob - c7771b4a68393727bf41bbc946aa8bf453fc98b8
file + lib/deflate.c
--- lib/deflate.c
+++ lib/deflate.c
@@ -35,7 +35,8 @@
 #endif
 
 const struct got_error *
-got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize)
+got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize,
+    struct got_deflate_checksum *csum)
 {
 	const struct got_error *err = NULL;
 	int zerr;
@@ -74,12 +75,23 @@ got_deflate_init(struct got_deflate_buf *zb, uint8_t *
 	} else
 		zb->outbuf = outbuf;
 
+	zb->csum = csum;
 done:
 	if (err)
 		got_deflate_end(zb);
 	return err;
 }
 
+static void
+csum_output(struct got_deflate_checksum *csum, const char *buf, size_t len)
+{
+	if (csum->output_crc)
+		*csum->output_crc = crc32(*csum->output_crc, buf, len);
+
+	if (csum->output_sha1)
+		SHA1Update(csum->output_sha1, buf, len);
+}
+
 const struct got_error *
 got_deflate_read(struct got_deflate_buf *zb, FILE *f, size_t *outlenp)
 {
@@ -92,6 +104,9 @@ got_deflate_read(struct got_deflate_buf *zb, FILE *f, 
 
 	*outlenp = 0;
 	do {
+		char *csum_out = NULL;
+		size_t csum_avail = 0;
+
 		if (z->avail_in == 0) {
 			size_t n = fread(zb->inbuf, 1, zb->inlen, f);
 			if (n == 0) {
@@ -104,7 +119,15 @@ got_deflate_read(struct got_deflate_buf *zb, FILE *f, 
 			z->next_in = zb->inbuf;
 			z->avail_in = n;
 		}
+		if (zb->csum) {
+			csum_out = z->next_out;
+			csum_avail = z->avail_out;
+		}
 		ret = deflate(z, Z_NO_FLUSH);
+		if (zb->csum) {
+			csum_output(zb->csum, csum_out,
+			   csum_avail - z->avail_out);
+		}
 	} while (ret == Z_OK && z->avail_out > 0);
 
 	if (ret == Z_OK) {
@@ -129,13 +152,14 @@ got_deflate_end(struct got_deflate_buf *zb)
 }
 
 const struct got_error *
-got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile)
+got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
+    struct got_deflate_checksum *csum)
 {
 	const struct got_error *err;
 	size_t avail;
 	struct got_deflate_buf zb;
 
-	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
+	err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE, csum);
 	if (err)
 		goto done;
 
@@ -157,8 +181,6 @@ got_deflate_to_file(size_t *outlen, FILE *infile, FILE
 	} while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
 
 done:
-	if (err == NULL)
-		rewind(outfile);
 	got_deflate_end(&zb);
 	return err;
 }
blob - 1777eab636e44eb4f1da022aa831a352eac52d5e
file + lib/got_lib_deflate.h
--- lib/got_lib_deflate.h
+++ lib/got_lib_deflate.h
@@ -14,6 +14,14 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
+struct got_deflate_checksum {
+	/* If not NULL, mix output bytes into this CRC checksum. */
+	uint32_t *output_crc;
+
+	/* If not NULL, mix output bytes into this SHA1 context. */
+	SHA1_CTX *output_sha1;
+};
+
 struct got_deflate_buf {
 	z_stream z;
 	char *inbuf;
@@ -23,13 +31,15 @@ struct got_deflate_buf {
 	int flags;
 #define GOT_DEFLATE_F_HAVE_MORE		0x01
 #define GOT_DEFLATE_F_OWN_OUTBUF	0x02
+	struct got_deflate_checksum *csum;
 };
 
 #define GOT_DEFLATE_BUFSIZE		8192
 
 const struct got_error *got_deflate_init(struct got_deflate_buf *, uint8_t *,
-    size_t);
+    size_t, struct got_deflate_checksum *);
 const struct got_error *got_deflate_read(struct got_deflate_buf *, FILE *,
     size_t *);
 void got_deflate_end(struct got_deflate_buf *);
-const struct got_error *got_deflate_to_file(size_t *, FILE *, FILE *);
+const struct got_error *got_deflate_to_file(size_t *, FILE *, FILE *,
+    struct got_deflate_checksum *);
blob - 5b8443903a0b59be4df01a675d1d07201d2df656
file + lib/object_create.c
--- lib/object_create.c
+++ lib/object_create.c
@@ -83,7 +83,7 @@ create_object_file(struct got_object_id *id, FILE *con
 		goto done;
 	}
 
-	err = got_deflate_to_file(&tmplen, content, tmpfile);
+	err = got_deflate_to_file(&tmplen, content, tmpfile, NULL);
 	if (err)
 		goto done;