refactored --list function

better handling of special conditions,
better scoping of variables.

Also : updated man page

1 files changed, 97 insertions, 79 deletions

diff --git a/programs/lz4io.c b/programs/lz4io.c
index 1e6efe1..e3eed93 100644
--- a/programs/lz4io.c
+++ b/programs/lz4io.c
@@ -1275,87 +1275,105 @@ typedef struct {
   LZ4F_frameInfo_t frameInfo;
   const char* fileName;
   unsigned long long fileSize;
-} LZ4F_compFileInfo_t;
-
-#define LZ4F_INIT_FILEINFO   { LZ4F_INIT_FRAMEINFO, NULL, 0ULL }
-
-
-static int LZ4IO_getCompressedFileInfo(const char* input_filename,  LZ4F_compFileInfo_t* cfinfo){
-  const char *b,
-             *e;
-  char *t;
-  stat_t statbuf;
-  size_t readSize = LZ4F_HEADER_SIZE_MAX;
-  LZ4F_errorCode_t errorCode;
-  dRess_t ress;
-  /* Open file */
-  FILE* const finput = LZ4IO_openSrcFile(input_filename);
-  if (finput==NULL) return 1;
-
-  /* Get file size */
-  if (!UTIL_getFileStat(input_filename, &statbuf)){
-    EXM_THROW(60, "Can't stat file : %s", input_filename);
-  }
-
-  cfinfo->fileSize = (unsigned long long)statbuf.st_size;
-
-  /* Get basename without extension */
-  b = strrchr(input_filename, '/');
-  if (!b){
-    b = strrchr(input_filename, '\\');
-  }
-  if (b && b != input_filename){
-    b++;
-  } else{
-    b=input_filename;
-  }
-  e = strrchr(b, '.');
-
-  /* Allocate Memory */
-  t = (char*)malloc( (size_t)(e-b+1) * sizeof(char));
-  ress.srcBuffer = malloc(LZ4IO_dBufferSize);
-  if (!t || !ress.srcBuffer)
-    EXM_THROW(21, "Allocation error : not enough memory");
-  strncpy(t, b, (e-b));
-  t[e-b] = '\0';
-  cfinfo->fileName = t;
-
-  /* init */
-  errorCode = LZ4F_createDecompressionContext(&ress.dCtx, LZ4F_VERSION);
-  if (LZ4F_isError(errorCode)) EXM_THROW(60, "Can't create LZ4F context : %s", LZ4F_getErrorName(errorCode));
-
-  if (!fread(ress.srcBuffer, readSize, 1, finput)){
-    EXM_THROW(30, "Error reading %s ", input_filename);
-  }
-  LZ4F_getFrameInfo(ress.dCtx, &cfinfo->frameInfo, ress.srcBuffer, &readSize);
-
-  /* Close input/free resources */
-  fclose(finput);
-  free(ress.srcBuffer);
-  return 0;
-}
+} LZ4IO_cFileInfo_t;
+
+#define LZ4IO_INIT_CFILEINFO   { LZ4F_INIT_FRAMEINFO, NULL, 0ULL }
+
+
+/* This function is limited,
+ * it only works fine for a file consisting of a single valid frame.
+ * It will / may stop program execution if a single filename is wrong.
+ * It will not look at content beyond first frame header.
+ *
+ * Things to improve :
+ * - continue execution after an error, just report an error code, keep all memory clean
+ * - check the entire file for additional content after first frame
+ *   + combine results from multiple frames, give total
+ * - Optional :
+ *  + report nb of blocks, hence max. possible decompressed size (when not reported in header)
+ *  + report block type (B4D, B7I, etc.)
+ */
+static int
+LZ4IO_getCompressedFileInfo(LZ4IO_cFileInfo_t* cfinfo, const char* input_filename)
+{
+    /* Get file size */
+    cfinfo->fileSize = UTIL_getFileSize(input_filename);  /* returns 0 if cannot read information */
 
-int LZ4IO_displayCompressedFilesInfo(const char** inFileNames, const size_t ifnIdx){
-  size_t idx;
-  int op_result=0;
-  double ratio;
-  DISPLAY("%16s\t%-20s\t%-20s\t%-10s\t%s\n","BlockChecksumFlag","Compressed", "Uncompressed", "Ratio", "Filename");
-  for(idx=0; idx<ifnIdx; idx++){
-    /* Get file info */
-    LZ4F_compFileInfo_t cfinfo = LZ4F_INIT_FILEINFO;
-    op_result=LZ4IO_getCompressedFileInfo(inFileNames[idx], &cfinfo);
-    if (op_result != 0){
-        DISPLAYLEVEL(1, "Failed to get frame info for file %s\n", inFileNames[idx]);
-        /* Don't bother trying to process any other file */
-        break;
+    /* Get filename without path prefix */
+    {   const char* b = strrchr(input_filename, '/');
+        if (!b) {
+            b = strrchr(input_filename, '\\');
+        }
+        if (b && b != input_filename) {
+            b++;
+        } else {
+            b = input_filename;
+        }
+        cfinfo->fileName = b;
     }
-    if(cfinfo.frameInfo.contentSize){
-        ratio = (double)cfinfo.fileSize / cfinfo.frameInfo.contentSize;
-        DISPLAY("%-16d\t%-20llu\t%-20llu\t%-8.4f\t%s\n",cfinfo.frameInfo.blockChecksumFlag,cfinfo.fileSize,cfinfo.frameInfo.contentSize, ratio, cfinfo.fileName);
+
+    /* Read file and extract header */
+    {   size_t readSize = LZ4F_HEADER_SIZE_MAX;
+        void* buffer = malloc(readSize);
+        LZ4F_dctx* dctx;
+
+        if (!buffer) EXM_THROW(21, "Allocation error : not enough memory");
+        {   LZ4F_errorCode_t const errorCode =
+                LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION);
+            if (LZ4F_isError(errorCode))
+                EXM_THROW(60, "Can't create LZ4F context : %s",
+                            LZ4F_getErrorName(errorCode));
+        }
+
+        {   FILE* const finput = LZ4IO_openSrcFile(input_filename);
+            if (finput==NULL) return 1;
+            if (!fread(buffer, readSize, 1, finput)) {
+                EXM_THROW(30, "Error reading %s ", input_filename);
+            }
+            fclose(finput);
+        }
+
+        {   LZ4F_errorCode_t const errorCode =
+                LZ4F_getFrameInfo(dctx, &cfinfo->frameInfo, buffer, &readSize);
+            if (LZ4F_isError(errorCode))
+                EXM_THROW(60, "Cannot interpret LZ4 frame : %s",
+                            LZ4F_getErrorName(errorCode));
+        }
+
+        /* clean */
+        free(buffer);
+        LZ4F_freeDecompressionContext(dctx);
     }
-    else{
-        DISPLAY("%-16d\t%-20llu\t%-20s\t%-10s\t%s\n",cfinfo.frameInfo.blockChecksumFlag,cfinfo.fileSize, "-", "-", cfinfo.fileName);
+
+    return 0;
+}
+
+int LZ4IO_displayCompressedFilesInfo(const char** inFileNames, const size_t ifnIdx)
+{
+    size_t idx;
+
+    DISPLAY("%16s\t%-20s\t%-20s\t%-10s\t%s\n",
+        "BlockChecksumFlag","Compressed", "Uncompressed", "Ratio", "Filename");
+
+    for (idx=0; idx<ifnIdx; idx++) {
+        /* Get file info */
+        LZ4IO_cFileInfo_t cfinfo = LZ4IO_INIT_CFILEINFO;
+        int const op_result = LZ4IO_getCompressedFileInfo(&cfinfo, inFileNames[idx]);
+        if (op_result != 0) {
+            DISPLAYLEVEL(1, "Failed to get frame info for file %s\n", inFileNames[idx]);
+            /* Don't bother processing any more file */
+            return 1;
+        }
+        if (cfinfo.frameInfo.contentSize) {
+            double const ratio = (double)cfinfo.fileSize / cfinfo.frameInfo.contentSize;
+            DISPLAY("%-16d\t%-20llu\t%-20llu\t%-8.4f\t%s\n",
+                    cfinfo.frameInfo.blockChecksumFlag, cfinfo.fileSize,
+                    cfinfo.frameInfo.contentSize, ratio, cfinfo.fileName);
+        } else {
+            DISPLAY("%-16d\t%-20llu\t%-20s\t%-10s\t%s\n",
+                    cfinfo.frameInfo.blockChecksumFlag, cfinfo.fileSize,
+                    "-", "-", cfinfo.fileName);
+        }
     }
-  }
-  return op_result;
+    return 0;
 }