Enable file compression on file rotation

doc/dlt_offline_logstorage.md

@@ -77,7 +77,7 @@ NOFiles=<number of files>            # Number of created files before oldest is
 SyncBehavior=<strategy>              # Specify sync strategy. Default: Sync'ed after every message. See Logstorage Ringbuffer Implementation below.
 EcuID=<ECUid>                        # Specify ECU identifier
 SpecificSize=<spec size in bytes>    # Store logs in storage devices after specific size is reached.
-GzipCompression=<ON/OFF>             # Write the logfiles with gzip compression.
+GzipCompression=<ON/FILE/OFF>        # Write the logfiles with gzip compression. ON: Continously, FILE: On file rotation
 OverwriteBehavior=<strategy>         # Specify overwrite strategy. Default: Delete oldest file and continue. See Logstorage Ringbuffer Implementation below.
 DisableNetwork=<ON/OFF>              # Specify if the message shall be routed to network client.
 ```

src/offlinelogstorage/dlt_offline_logstorage.c

@@ -1337,7 +1337,11 @@ DLT_STATIC int dlt_logstorage_check_gzip_compression(DltLogStorageFilterConfig *
 
     if (strcasestr(value, "ON") != NULL) {
         config->gzip_compression = DLT_LOGSTORAGE_GZIP_ON;
-    } else if (strcasestr(value, "OFF") != NULL) {
+    }
+    else if (strcasestr(value, "FILE") != NULL) {
+        config->gzip_compression = DLT_LOGSTORAGE_GZIP_FILE;
+    }
+    else if (strcasestr(value, "OFF") != NULL) {
         config->gzip_compression = DLT_LOGSTORAGE_GZIP_OFF;
     } else {
         dlt_log(LOG_WARNING, "Unknown gzip compression flag\n");

src/offlinelogstorage/dlt_offline_logstorage.h

@@ -123,11 +123,14 @@
 #define DLT_LOGSTORAGE_DISABLE_NW_OFF            1 /* default, enable network routing */
 #define DLT_LOGSTORAGE_DISABLE_NW_ON            (1 << 1) /* disable network routing */
 
-/* Offline Logstorage disable network routing */
+/* Offline Logstorage enable gzip compression */
 #define DLT_LOGSTORAGE_GZIP_ERROR               -1 /* error case */
 #define DLT_LOGSTORAGE_GZIP_UNSET                0 /* not set */
 #define DLT_LOGSTORAGE_GZIP_OFF 1                  /* default, no compression */
-#define DLT_LOGSTORAGE_GZIP_ON (1 << 1)            /* enable gzip compression */
+#define DLT_LOGSTORAGE_GZIP_ON                                                 \
+    (1 << 1) /* enable gzip compression of all files */
+#define DLT_LOGSTORAGE_GZIP_FILE                                               \
+    (1 << 2) /* enable gzip compression on file rotation */
 
 /* logstorage max cache */
 extern unsigned int g_logstorage_cache_max;

src/offlinelogstorage/dlt_offline_logstorage_behavior.c

@@ -372,7 +372,8 @@ int dlt_logstorage_storage_dir_info(DltLogStorageUserConfig *file_config,
         config->records = NULL;
     }
 
-    char *suffix = config->gzip_compression == DLT_LOGSTORAGE_GZIP_ON ? ".dlt.gz" : ".dlt";
+    char *suffix = ".dlt.gz";
+    char *gzsuffix = ".dlt";
 
     for (i = 0; i < cnt; i++) {
         int len = 0;
@@ -385,10 +386,13 @@ int dlt_logstorage_storage_dir_info(DltLogStorageUserConfig *file_config,
             if (config->num_files == 1 && file_config->logfile_optional_counter) {
                 /* <filename>.dlt or <filename>_<tmsp>.dlt */
                 if ((files[i]->d_name[len] == suffix[0]) ||
+                    (files[i]->d_name[len] == gzsuffix[0]) ||
                     (file_config->logfile_timestamp &&
-                     (files[i]->d_name[len] == file_config->logfile_delimiter))) {
+                     (files[i]->d_name[len] ==
+                      file_config->logfile_delimiter))) {
                     current_idx = 1;
-                } else {
+                }
+                else {
                     continue;
                 }
             } else {
@@ -732,6 +736,29 @@ int dlt_logstorage_open_log_file(DltLogStorageFilterConfig *config,
                 }
             }
 
+#ifdef DLT_LOGSTORAGE_USE_GZIP
+            if (config->gzip_compression == DLT_LOGSTORAGE_GZIP_FILE) {
+                tmp = &config->records;
+                while ((*tmp)->next != NULL) {
+                    int len = strlen((*tmp)->name);
+                    const char *suffix = ".dlt";
+                    if (strcmp(&(*tmp)->name[len - strlen(suffix)], suffix) ==
+                        0) {
+                        memset(absolute_file_path, 0,
+                               sizeof(absolute_file_path) / sizeof(char));
+                        strcat(absolute_file_path, storage_path);
+                        strncat(absolute_file_path, (*tmp)->name, len);
+                        dlt_vlog(LOG_INFO,
+                                 "%s: Compressing '%s' (num_log_files: %d, "
+                                 "file_name:%s)\n",
+                                 __func__, absolute_file_path, num_log_files,
+                                 (*tmp)->name);
+                        dlt_logstorage_compress_dlt_file(absolute_file_path);
+                    }
+                    tmp = &(*tmp)->next;
+                }
+            }
+#endif
         }
     }
 
@@ -761,6 +788,114 @@ int dlt_logstorage_open_log_file(DltLogStorageFilterConfig *config,
     return ret;
 }
 
+#ifdef DLT_LOGSTORAGE_USE_GZIP
+/**
+ * dlt_logstorage_compress_dlt_file
+ *
+ * Compress content of a file and remove the original file.
+ * compressed file name is the same as the original with .gz extension.
+ *
+ * @param file_path    The file to compress
+ * @return 0 on success, -1 on error
+ */
+int dlt_logstorage_compress_dlt_file(char *file_path)
+{
+    char file_path_dest[DLT_OFFLINE_LOGSTORAGE_MAX_PATH_LEN + 1] = {'\0'};
+    strcat(file_path_dest, file_path);
+    strcat(file_path_dest, ".gz");
+
+    FILE *source = fopen(file_path, "rb");
+    if (source == NULL) {
+        dlt_vlog(LOG_ERR, "%s: could not open %s\n", __func__, file_path);
+        return -1;
+    }
+
+    FILE *dest = fopen(file_path_dest, "wb");
+    if (dest == NULL) {
+        dlt_vlog(LOG_ERR, "%s: could not open %s\n", __func__, file_path_dest);
+        fclose(source);
+        return -1;
+    }
+
+    gzFile gzfile = gzdopen(fileno(dest), "wb");
+    if (dest == NULL) {
+        dlt_vlog(LOG_ERR, "%s: could not gz open %s\n", __func__,
+                 file_path_dest);
+        fclose(source);
+        fclose(dest);
+        return -1;
+    }
+
+    int ret = dlt_logstorage_compress_fd(source, gzfile);
+
+    fclose(source);
+    gzclose(gzfile);
+    fclose(dest);
+
+    if (ret == 0 && remove(file_path) != 0) {
+        dlt_vlog(LOG_ERR, "%s: could not remove original file %s \n", __func__,
+                 file_path);
+        return -1;
+    }
+
+    return ret;
+}
+#endif
+
+#ifdef DLT_LOGSTORAGE_USE_GZIP
+/**
+ * dlt_logstorage_compress_fd
+ *
+ * Compress content of a file descriptor into a gzFile.
+ *
+ * @param source    The file to compress
+ * @param dest      The file to write to
+ * @return 0 on success, -1 on error
+ */
+int dlt_logstorage_compress_fd(FILE *source, gzFile dest)
+{
+    int ret, flush;
+    z_stream strm;
+    unsigned char in[COMPRESS_CHUNK];
+
+    /* allocate deflate state */
+    strm.zalloc = Z_NULL;
+    strm.zfree = Z_NULL;
+    strm.opaque = Z_NULL;
+    ret = deflateInit(&strm, Z_DEFAULT_COMPRESSION);
+    if (ret != Z_OK)
+        return ret;
+
+    /* compress until end of file */
+    do {
+        strm.avail_in = fread(in, 1, COMPRESS_CHUNK, source);
+        if (ferror(source)) {
+            (void)deflateEnd(&strm);
+            dlt_vlog(LOG_ERR, "%s: Can't open source\n", __func__);
+            return -1;
+        }
+
+        ret = gzwrite(dest, in, strm.avail_in);
+        if (ret == 0) {
+            (void)deflateEnd(&strm);
+            dlt_vlog(LOG_ERR, "%s: failed to write to log file\n", __func__);
+            return -1;
+        }
+        if (gzflush(dest, Z_SYNC_FLUSH) != 0)
+            dlt_vlog(LOG_ERR, "%s: failed to gzflush log file\n", __func__);
+
+        flush = feof(source) ? Z_FINISH : Z_NO_FLUSH;
+        strm.next_in = in;
+
+        // done when last data in file processed
+    } while (flush != Z_FINISH);
+
+    // clean up and return
+    (void)deflateEnd(&strm);
+    return 0;
+}
+#endif
+
 /**
  * dlt_logstorage_find_dlt_header
  *

src/offlinelogstorage/dlt_offline_logstorage_behavior_internal.h

@@ -75,6 +75,12 @@ int dlt_logstorage_open_log_file(DltLogStorageFilterConfig *config,
                                  bool is_update_required,
                                  bool is_sync);
 
+#ifdef DLT_LOGSTORAGE_USE_GZIP
+#define COMPRESS_CHUNK 16384
+int dlt_logstorage_compress_dlt_file(char *path);
+int dlt_logstorage_compress_fd(FILE *source, gzFile dest);
+#endif
+
 DLT_STATIC int dlt_logstorage_sync_to_file(DltLogStorageFilterConfig *config,
                                            DltLogStorageUserConfig *file_config,
                                            char *dev_path,