From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 11 Jan 2025 13:20:22 +0000 (+0000)
Subject: util: Create a convenience function to map files into memory
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=01709cf0df33b3246cf90b632de54d75c447ec1a;p=people%2Fric9%2Fpakfire.git

util: Create a convenience function to map files into memory

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/pakfire/file.c b/src/pakfire/file.c
index 6e1be494e..13b34f53c 100644
--- a/src/pakfire/file.c
+++ b/src/pakfire/file.c
@@ -1131,8 +1131,6 @@ FILE* pakfire_file_fopen(struct pakfire_file* file, const char* mode) {
 	Opens the file and returns a mapping of the payload in memory
 */
 static int pakfire_file_mmap(struct pakfire_file* file, char** data, size_t* length) {
-	struct stat st = {};
-	char* buffer = NULL;
 	int fd = -EBADF;
 	int r;
 
@@ -1141,26 +1139,13 @@ static int pakfire_file_mmap(struct pakfire_file* file, char** data, size_t* len
 	if (fd < 0)
 		goto ERROR;
 
-	// Stat the file
-	r = fstat(fd, &st);
+	// Map the file
+	r = pakfire_mmap(fd, data, length);
 	if (r < 0) {
-		ERROR(file->ctx, "Could not stat %s: %m\n", pakfire_file_get_path(file));
-		r = -errno;
-		goto ERROR;
-	}
-
-	// Map the data
-	buffer = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-	if (buffer == MAP_FAILED) {
-		ERROR(file->ctx, "Could not map %s: %m\n", pakfire_file_get_path(file));
-		r = -errno;
+		ERROR(file->ctx, "Could not map %s: %s\n", pakfire_file_get_path(file), strerror(-r));
 		goto ERROR;
 	}
 
-	// Return the values
-	*data = buffer;
-	*length = st.st_size;
-
 ERROR:
 	if (fd >= 0)
 		close(fd);
diff --git a/src/pakfire/util.c b/src/pakfire/util.c
index 943b80826..634c45f0c 100644
--- a/src/pakfire/util.c
+++ b/src/pakfire/util.c
@@ -23,6 +23,7 @@
 #include <ftw.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/mman.h>
 #include <sys/resource.h>
 
 #include <json.h>
@@ -132,6 +133,37 @@ int pakfire_read_file_into_buffer(FILE* f, char** buffer, size_t* len) {
 	return 0;
 }
 
+/*
+	Maps a file descriptor into memory
+*/
+int pakfire_mmap(int fd, char** data, size_t* length) {
+	char* buffer = NULL;
+	struct stat st = {};
+	int r;
+
+	// Check inputs
+	if (fd < 0)
+		return -EBADF;
+	else if (!data || !length)
+		return -EINVAL;
+
+	// Stat the file
+	r = fstat(fd, &st);
+	if (r < 0)
+		return -errno;
+
+	// Map the data
+	buffer = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	if (buffer == MAP_FAILED)
+		return -errno;
+
+	// Return the values
+	*data   = buffer;
+	*length = st.st_size;
+
+	return 0;
+}
+
 char* pakfire_generate_uuid(void) {
 	uuid_t uuid;
 
diff --git a/src/pakfire/util.h b/src/pakfire/util.h
index b2cdf80f1..6310face7 100644
--- a/src/pakfire/util.h
+++ b/src/pakfire/util.h
@@ -43,6 +43,7 @@ static inline void* pakfire_realloc(void* p, size_t size) {
 }
 
 int pakfire_read_file_into_buffer(FILE* f, char** buffer, size_t* len);
+int pakfire_mmap(int fd, char** data, size_t* length);
 
 const char* pakfire_path_relpath(const char* root, const char* path);