tree-wide: add new HAVE_COMPRESSION compile time flag

let's simplify the checks for ZSTD/LZ4/XZ

As suggested:

https://github.com/systemd/systemd/pull/16096#discussion_r440705585

src/coredump/coredump.c

@@ -423,7 +423,7 @@ static int save_external_coredump(
                 goto fail;
         }
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         /* If we will remove the coredump anyway, do not compress. */
         if (arg_compress && !maybe_remove_external_coredump(NULL, st.st_size)) {
 

src/coredump/coredumpctl.c

@@ -824,7 +824,7 @@ static int save_core(sd_journal *j, FILE *file, char **path, bool *unlink_temp)
         }
 
         if (filename) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
                 _cleanup_close_ int fdf;
 
                 fdf = open(filename, O_RDONLY | O_CLOEXEC);

src/journal/journal-file.c

@@ -392,7 +392,7 @@ JournalFile* journal_file_close(JournalFile *f) {
 
         ordered_hashmap_free_free(f->chain_cache);
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         free(f->compress_buffer);
 #endif
 
@@ -1455,7 +1455,7 @@ int journal_file_find_data_object_with_hash(
                         goto next;
 
                 if (o->object.flags & OBJECT_COMPRESSION_MASK) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
                         uint64_t l;
                         size_t rsize = 0;
 
@@ -1624,7 +1624,7 @@ static int journal_file_append_data(
 
         o->data.hash = htole64(hash);
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         if (JOURNAL_FILE_COMPRESS(f) && size >= f->compress_threshold_bytes) {
                 size_t rsize = 0;
 
@@ -3852,7 +3852,7 @@ int journal_file_copy_entry(JournalFile *from, JournalFile *to, Object *o, uint6
                         return -E2BIG;
 
                 if (o->object.flags & OBJECT_COMPRESSION_MASK) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
                         size_t rsize = 0;
 
                         r = decompress_blob(o->object.flags & OBJECT_COMPRESSION_MASK,

src/journal/journal-file.h

@@ -107,7 +107,7 @@ typedef struct JournalFile {
         unsigned last_seen_generation;
 
         uint64_t compress_threshold_bytes;
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         void *compress_buffer;
         size_t compress_buffer_size;
 #endif

src/journal/sd-journal.c

@@ -2327,7 +2327,7 @@ _public_ int sd_journal_get_data(sd_journal *j, const char *field, const void **
 
                 compression = o->object.flags & OBJECT_COMPRESSION_MASK;
                 if (compression) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
                         r = decompress_startswith(compression,
                                                   o->data.payload, l,
                                                   &f->compress_buffer, &f->compress_buffer_size,
@@ -2394,7 +2394,7 @@ static int return_data(sd_journal *j, JournalFile *f, Object *o, const void **da
 
         compression = o->object.flags & OBJECT_COMPRESSION_MASK;
         if (compression) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
                 size_t rsize;
                 int r;
 

src/journal/test-compress-benchmark.c

@@ -17,7 +17,7 @@ typedef int (compress_t)(const void *src, uint64_t src_size, void *dst,
 typedef int (decompress_t)(const void *src, uint64_t src_size,
                            void **dst, size_t *dst_alloc_size, size_t* dst_size, size_t dst_max);
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
 
 static usec_t arg_duration;
 static size_t arg_start;
@@ -143,7 +143,7 @@ static void test_compress_decompress(const char* label, const char* type,
 #endif
 
 int main(int argc, char *argv[]) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         test_setup_logging(LOG_INFO);
 
         if (argc >= 2) {

src/journal/test-compress.c

@@ -44,7 +44,7 @@ typedef int (decompress_sw_t)(const void *src, uint64_t src_size,
 typedef int (compress_stream_t)(int fdf, int fdt, uint64_t max_bytes);
 typedef int (decompress_stream_t)(int fdf, int fdt, uint64_t max_size);
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
 _unused_ static void test_compress_decompress(const char *compression,
                                               compress_blob_t compress,
                                               decompress_blob_t decompress,
@@ -265,7 +265,7 @@ static void test_lz4_decompress_partial(void) {
 #endif
 
 int main(int argc, char *argv[]) {
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         _unused_ const char text[] =
                 "text\0foofoofoofoo AAAA aaaaaaaaa ghost busters barbarbar FFF"
                 "foofoofoofoo AAAA aaaaaaaaa ghost busters barbarbar FFF";

src/journal/test-journal.c

@@ -157,7 +157,7 @@ static void test_empty(void) {
         (void) journal_file_close(f4);
 }
 
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
 static bool check_compressed(uint64_t compress_threshold, uint64_t data_size) {
         dual_timestamp ts;
         JournalFile *f;
@@ -251,7 +251,7 @@ int main(int argc, char *argv[]) {
 
         test_non_empty();
         test_empty();
-#if HAVE_XZ || HAVE_LZ4 || HAVE_ZSTD
+#if HAVE_COMPRESSION
         test_min_compress_size();
 #endif