compress: introduce compression_supported() helper function

2 files changed, 13 insertions, 0 deletions

diff --git a/src/basic/compress.c b/src/basic/compress.c
index 0a330ecb55..59621dc05b 100644
--- a/src/basic/compress.c
+++ b/src/basic/compress.c
@@ -65,6 +65,16 @@ static const char* const compression_table[_COMPRESSION_MAX] = {
 
 DEFINE_STRING_TABLE_LOOKUP(compression, Compression);
 
+bool compression_supported(Compression c) {
+        static const unsigned supported =
+                (1U << COMPRESSION_NONE) |
+                (1U << COMPRESSION_XZ) * HAVE_XZ |
+                (1U << COMPRESSION_LZ4) * HAVE_LZ4 |
+                (1U << COMPRESSION_ZSTD) * HAVE_ZSTD;
+
+        return c >= 0 && c < _COMPRESSION_MAX && FLAGS_SET(supported, 1U << c);
+}
+
 int compress_blob_xz(const void *src, uint64_t src_size,
                      void *dst, size_t dst_alloc_size, size_t *dst_size) {
 #if HAVE_XZ
diff --git a/src/basic/compress.h b/src/basic/compress.h
index 583b105c66..2201bca74c 100644
--- a/src/basic/compress.h
+++ b/src/basic/compress.h
@@ -2,6 +2,7 @@
 #pragma once
 
 #include <errno.h>
+#include <stdbool.h>
 #include <stdint.h>
 #include <unistd.h>
 
@@ -17,6 +18,8 @@ typedef enum Compression {
 const char* compression_to_string(Compression compression);
 Compression compression_from_string(const char *compression);
 
+bool compression_supported(Compression c);
+
 int compress_blob_xz(const void *src, uint64_t src_size,
                      void *dst, size_t dst_alloc_size, size_t *dst_size);
 int compress_blob_lz4(const void *src, uint64_t src_size,