From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 8 Feb 2025 10:55:57 +0000 (+0000)
Subject: archive writer: Configure libarchive depending on the format
X-Git-Tag: 0.9.30~81
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5c19f150cef47bcd736a223cad9cdafaec150178;p=pakfire.git

archive writer: Configure libarchive depending on the format

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

diff --git a/src/pakfire/archive_writer.c b/src/pakfire/archive_writer.c
index c734ffc1..2e3fdf83 100644
--- a/src/pakfire/archive_writer.c
+++ b/src/pakfire/archive_writer.c
@@ -22,7 +22,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+// libarchive
+#include <archive.h>
+#include <archive_entry.h>
+
 #include <pakfire/archive_writer.h>
+#include <pakfire/string.h>
 
 struct pakfire_archive_writer {
 	struct pakfire_ctx* ctx;
@@ -34,11 +39,162 @@ struct pakfire_archive_writer {
 	// Format
 	pakfire_archive_writer_format format;
 
+	// Container
+	enum pakfire_archive_writer_container {
+		PAKFIRE_CONTAINER_PAX,
+	} container;
+
+	// Compression
+	enum pakfire_archive_writer_compression {
+		PAKFIRE_COMPRESSION_NONE,
+		PAKFIRE_COMPRESSION_ZSTD,
+	} compression;
+	unsigned int compression_level;
+
 	// File Handle
 	FILE* f;
+
+	// Archive
+	struct archive* archive;
 };
 
+/*
+ * This function configures this object depending on the format.
+ */
+static int pakfire_archive_writer_setup_format(
+		struct pakfire_archive_writer* self, pakfire_archive_writer_format format) {
+	switch (format) {
+		// The Pakfire Archive Format
+		case PAKFIRE_FORMAT_ARCHIVE:
+			// We use the PAX tar format
+			self->container = PAKFIRE_CONTAINER_PAX;
+
+			// We use Zstandard compression
+			self->compression = PAKFIRE_COMPRESSION_ZSTD;
+
+			// Use some good compression
+			self->compression_level = 20;
+			break;
+
+		// Fail on invalid inputs
+		default:
+			ERROR(self->ctx, "Invalid archive format\n");
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int pakfire_archive_writer_setup_archive(struct pakfire_archive_writer* self) {
+	char value[64];
+	int r;
+
+	// Open a new archive
+	self->archive = archive_write_new();
+	if (!self->archive) {
+		ERROR(self->ctx, "archive_write_new() failed\n");
+		return -ENOTSUP;
+	}
+
+	// Set the container format
+	switch (self->container) {
+		case PAKFIRE_CONTAINER_PAX:
+			// Use the PAX format
+			r = archive_write_set_format_pax(self->archive);
+			if (r) {
+				ERROR(self->ctx, "Could not set format to PAX: %s\n",
+					archive_error_string(self->archive));
+				return -ENOTSUP;
+			}
+
+			// Store any extended attributes in the SCHILY headers
+			r = archive_write_set_format_option(self->archive, "pax", "xattrheader", "SCHILY");
+			if (r) {
+				ERROR(self->ctx, "Could not set xattrheader option: %s\n",
+					archive_error_string(self->archive));
+				return -ENOTSUP;
+			}
+			break;
+	}
+
+	// Set the compression
+	switch (self->compression) {
+		case PAKFIRE_COMPRESSION_NONE:
+			break;
+
+		// Zstandard
+		case PAKFIRE_COMPRESSION_ZSTD:
+			r = archive_write_add_filter_zstd(self->archive);
+			if (r) {
+				ERROR(self->ctx, "Could not enable Zstandard compression: %s\n",
+					archive_error_string(self->archive));
+				return -ENOTSUP;
+			}
+
+			// Do not pad the last block
+			archive_write_set_bytes_in_last_block(self->archive, 1);
+
+#if ARCHIVE_VERSION_NUMBER >= 3007002
+			// Enable long mode (supported from libarchive >= 3.7.2)
+			r = archive_write_set_filter_option(self->archive, NULL, "long", "31");
+			if (r) {
+				ERROR(self->ctx, "Failed to enable Zstandard long mode: %s\n",
+					archive_error_string(self->archive));
+				return -ENOTSUP;
+			}
+#endif /* ARCHIVE_VERSION_NUMBER >= 3007002 */
+
+#if ARCHIVE_VERSION_NUMBER >= 3006000
+			// Fetch numbers of processors
+			long processors = sysconf(_SC_NPROCESSORS_ONLN);
+
+			if (processors > 1) {
+				r = pakfire_string_format(value, "%ld", processors);
+				if (r)
+					return r;
+
+				// Try using multiple threads
+				r = archive_write_set_filter_option(self->archive, NULL, "threads", value);
+				if (r) {
+					ERROR(self->ctx, "Could not enable %ld threads for compression: %s\n",
+						processors, archive_error_string(self->archive));
+					return -ENOTSUP;
+				}
+			}
+#endif
+			break;
+	}
+
+	// Set compression level
+	if (self->compression_level) {
+		// Format the value
+		r = pakfire_string_format(value, "%u", self->compression_level);
+		if (r < 0)
+			return r;
+
+		// Set the value
+		r = archive_write_set_filter_option(self->archive, NULL, "compression-level", value);
+		if (r) {
+			ERROR(self->ctx, "Could not set compression level %s: %s\n",
+				value, archive_error_string(self->archive));
+			return -ENOTSUP;
+		}
+	}
+
+	// Write archive to f
+	r = archive_write_open_FILE(self->archive, self->f);
+	if (r) {
+		ERROR(self->ctx, "archive_write_open_FILE() failed: %s\n",
+			archive_error_string(self->archive));
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
 static void pakfire_archive_writer_free(struct pakfire_archive_writer* self) {
+	if (self->archive)
+		archive_write_free(self->archive);
 	if (self->pakfire)
 		pakfire_unref(self->pakfire);
 	if (self->ctx)
@@ -65,21 +221,19 @@ int pakfire_archive_writer_create(struct pakfire_archive_writer** writer,
 	// Initialize the reference counter
 	self->nrefs = 1;
 
-	// Store the format
-	switch (format) {
-		case PAKFIRE_FORMAT_ARCHIVE:
-			self->format = format;
-			break;
-
-		default:
-			ERROR(self->ctx, "Invalid archive format\n");
-			r = -EINVAL;
-			goto ERROR;
-	}
-
 	// Store the file handle
 	self->f = f;
 
+	// Setup format
+	r = pakfire_archive_writer_setup_format(self, format);
+	if (r < 0)
+		goto ERROR;
+
+	// Setup archive
+	r = pakfire_archive_writer_setup_archive(self);
+	if (r < 0)
+		goto ERROR;
+
 	// Return the pointer
 	*writer = self;
 	return 0;