From: Joel Rosdahl <joel@rosdahl.net>
Date: Sat, 29 Jun 2019 18:37:08 +0000 (+0200)
Subject: Refactor functions for reading/writing common header
X-Git-Tag: v4.0~927
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=206c85c1f39fbeb948af0556938cd51e9b79fdb4;p=thirdparty%2Fccache.git

Refactor functions for reading/writing common header

The functions now work on bytes instead of FILEs, allowing for the
caller to optionally peek at read/written bytes.
---

diff --git a/src/common_header.c b/src/common_header.c
index ebfb18398..50e998978 100644
--- a/src/common_header.c
+++ b/src/common_header.c
@@ -19,7 +19,7 @@
 #include "compression.h"
 #include "common_header.h"
 
-void common_header_init_from_config(
+void common_header_from_config(
 	struct common_header *header,
 	const char magic[4],
 	uint8_t RESULT_VERSION,
@@ -35,29 +35,24 @@ void common_header_init_from_config(
 	header->content_size = content_size;
 }
 
-bool common_header_init_from_file(struct common_header *header, FILE *f)
+void
+common_header_from_bytes(struct common_header *header, uint8_t *buffer)
 {
-	char buffer[COMMON_HEADER_SIZE];
-	if (fread(buffer, 1, sizeof(buffer), f) != sizeof(buffer)) {
-		return false;
-	}
 	memcpy(header->magic, buffer, 4);
 	header->version = buffer[4];
 	header->compression_type = buffer[5];
 	header->compression_level = buffer[6];
 	header->content_size = UINT64_FROM_BYTES(buffer + 7);
-	return true;
 }
 
-bool common_header_write_to_file(const struct common_header *header, FILE *f)
+void
+common_header_to_bytes(const struct common_header *header, uint8_t *buffer)
 {
-	char buffer[COMMON_HEADER_SIZE];
 	memcpy(buffer, header->magic, 4);
 	buffer[4] = header->version;
 	buffer[5] = header->compression_type;
 	buffer[6] = header->compression_level;
 	BYTES_FROM_UINT64(buffer + 7, header->content_size);
-	return fwrite(buffer, 1, sizeof(buffer), f) == sizeof(buffer);
 }
 
 bool common_header_verify(
diff --git a/src/common_header.h b/src/common_header.h
index def2ee209..f25e3a1b5 100644
--- a/src/common_header.h
+++ b/src/common_header.h
@@ -1,3 +1,6 @@
+#ifndef COMMON_HEADER_H
+#define COMMON_HEADER_H
+
 #define COMMON_HEADER_SIZE 15
 
 struct common_header {
@@ -8,13 +11,16 @@ struct common_header {
 	uint64_t content_size;
 };
 
-void common_header_init_from_config(
+void common_header_from_config(
 	struct common_header *header,
 	const char magic[4],
 	uint8_t RESULT_VERSION,
 	uint64_t content_size);
-bool common_header_init_from_file(struct common_header *header, FILE *f);
-bool common_header_write_to_file(const struct common_header *header, FILE *f);
+void common_header_from_bytes(struct common_header *header, uint8_t *bytes);
+void common_header_to_bytes(
+	const struct common_header *header, uint8_t *bytes);
 bool common_header_verify(
 	const struct common_header *header, int fd, const char *name, char **errmsg);
 void common_header_dump(const struct common_header *header, FILE *f);
+
+#endif
diff --git a/src/manifest.c b/src/manifest.c
index 6dddba5b0..171745ce5 100644
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -252,11 +252,14 @@ read_manifest(const char *path, char **errmsg)
 		goto out;
 	}
 
-	if (!common_header_init_from_file(&mf->header, f)) {
+	uint8_t header_bytes[COMMON_HEADER_SIZE];
+	if (fread(header_bytes, sizeof(header_bytes), 1, f) != 1) {
 		*errmsg = format("Failed to read header from %s", path);
 		goto out;
 	}
 
+	common_header_from_bytes(&mf->header, header_bytes);
+
 	if (memcmp(mf->header.magic, MAGIC, sizeof(MAGIC)) != 0) {
 		*errmsg = format(
 			"Result file has bad magic value 0x%x%x%x%x",
@@ -393,9 +396,10 @@ write_manifest(FILE *f, const struct manifest *mf)
 	}
 
 	struct common_header header;
-	common_header_init_from_config(
-		&header, MAGIC, MANIFEST_VERSION, content_size);
-	if (!common_header_write_to_file(&header, f)) {
+	common_header_from_config(&header, MAGIC, MANIFEST_VERSION, content_size);
+	uint8_t header_bytes[COMMON_HEADER_SIZE];
+	common_header_to_bytes(&header, header_bytes);
+	if (fwrite(header_bytes, sizeof(header_bytes), 1, f) != 1) {
 		goto error;
 	}
 
diff --git a/src/result.c b/src/result.c
index adc5639ee..8ad039faa 100644
--- a/src/result.c
+++ b/src/result.c
@@ -163,12 +163,15 @@ read_result(
 		goto out;
 	}
 
-	struct common_header header;
-	if (!common_header_init_from_file(&header, f)) {
+	uint8_t header_bytes[COMMON_HEADER_SIZE];
+	if (fread(header_bytes, sizeof(header_bytes), 1, f) != 1) {
 		*errmsg = format("Failed to read header from %s", path);
 		goto out;
 	}
 
+	struct common_header header;
+	common_header_from_bytes(&header, header_bytes);
+
 	if (memcmp(header.magic, MAGIC, sizeof(MAGIC)) != 0) {
 		*errmsg = format(
 			"Result file has bad magic value 0x%x%x%x%x",
@@ -404,8 +407,11 @@ bool result_put(const char *path, struct result_files *list)
 	}
 
 	struct common_header header;
-	common_header_init_from_config(&header, MAGIC, RESULT_VERSION, content_size);
-	if (!common_header_write_to_file(&header, f)) {
+	common_header_from_config(&header, MAGIC, RESULT_VERSION, content_size);
+
+	uint8_t header_bytes[COMMON_HEADER_SIZE];
+	common_header_to_bytes(&header, header_bytes);
+	if (fwrite(header_bytes, sizeof(header_bytes), 1, f) != 1) {
 		cc_log("Failed to write result file header to %s", tmp_file);
 		goto out;
 	}