vendor/zstd/1.3.0

1 files changed, 302 insertions, 275 deletions

diff --git a/zlibWrapper/zstd_zlibwrapper.c b/zlibWrapper/zstd_zlibwrapper.c
index 1960d19e970c..ade3b88cd1f4 100644
--- a/zlibWrapper/zstd_zlibwrapper.c
+++ b/zlibWrapper/zstd_zlibwrapper.c
@@ -8,35 +8,42 @@
  */
 
 
+/* ===   Tuning parameters   === */
+#ifndef ZWRAP_USE_ZSTD
+    #define ZWRAP_USE_ZSTD 0
+#endif
+
+
+/* ===   Dependencies   === */
+#include <stdlib.h>
 #include <stdio.h>                 /* vsprintf */
 #include <stdarg.h>                /* va_list, for z_gzprintf */
 #define NO_DUMMY_DECL
 #define ZLIB_CONST
 #include <zlib.h>                  /* without #define Z_PREFIX */
 #include "zstd_zlibwrapper.h"
-#define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_MAGICNUMBER */
+#define ZSTD_STATIC_LINKING_ONLY   /* ZSTD_isFrame, ZSTD_MAGICNUMBER */
 #include "zstd.h"
-#include "zstd_internal.h"         /* defaultCustomMem */
+#include "zstd_internal.h"         /* ZSTD_malloc, ZSTD_free */
 
 
+/* ===   Constants   === */
 #define Z_INFLATE_SYNC              8
 #define ZLIB_HEADERSIZE             4
 #define ZSTD_HEADERSIZE             ZSTD_frameHeaderSize_min
 #define ZWRAP_DEFAULT_CLEVEL        3   /* Z_DEFAULT_COMPRESSION is translated to ZWRAP_DEFAULT_CLEVEL for zstd */
 
-#define LOG_WRAPPERC(...)  /* printf(__VA_ARGS__) */
-#define LOG_WRAPPERD(...)  /* printf(__VA_ARGS__) */
+
+/* ===   Debug   === */
+#define LOG_WRAPPERC(...)  /* fprintf(stderr, __VA_ARGS__) */
+#define LOG_WRAPPERD(...)  /* fprintf(stderr, __VA_ARGS__) */
 
 #define FINISH_WITH_GZ_ERR(msg) { (void)msg; return Z_STREAM_ERROR; }
 #define FINISH_WITH_NULL_ERR(msg) { (void)msg; return NULL; }
 
 
-
-#ifndef ZWRAP_USE_ZSTD
-    #define ZWRAP_USE_ZSTD 0
-#endif
-
-static int g_ZWRAP_useZSTDcompression = ZWRAP_USE_ZSTD;   /* 0 = don't use ZSTD */
+/* ===   Wrapper   === */
+static int g_ZWRAP_useZSTDcompression = ZWRAP_USE_ZSTD; /* 0 = don't use ZSTD */
 
 void ZWRAP_useZSTDcompression(int turn_on) { g_ZWRAP_useZSTDcompression = turn_on; }
 
@@ -62,7 +69,7 @@ static void* ZWRAP_allocFunction(void* opaque, size_t size)
 {
     z_streamp strm = (z_streamp) opaque;
     void* address = strm->zalloc(strm->opaque, 1, (uInt)size);
-  /*  printf("ZWRAP alloc %p, %d \n", address, (int)size); */
+    /* LOG_WRAPPERC("ZWRAP alloc %p, %d \n", address, (int)size); */
     return address;
 }
 
@@ -70,12 +77,12 @@ static void ZWRAP_freeFunction(void* opaque, void* address)
 {
     z_streamp strm = (z_streamp) opaque;
     strm->zfree(strm->opaque, address);
-   /* if (address) printf("ZWRAP free %p \n", address); */
+   /* if (address) LOG_WRAPPERC("ZWRAP free %p \n", address); */
 }
 
 
 
-/* *** Compression *** */
+/* ===   Compression   === */
 typedef enum { ZWRAP_useInit, ZWRAP_useReset, ZWRAP_streamEnd } ZWRAP_state_t;
 
 typedef struct {
@@ -95,16 +102,16 @@ typedef ZWRAP_CCtx internal_state;
 
 
 
-size_t ZWRAP_freeCCtx(ZWRAP_CCtx* zwc)
+static size_t ZWRAP_freeCCtx(ZWRAP_CCtx* zwc)
 {
     if (zwc==NULL) return 0;   /* support free on NULL */
-    if (zwc->zbc) ZSTD_freeCStream(zwc->zbc);
-    zwc->customMem.customFree(zwc->customMem.opaque, zwc);
+    ZSTD_freeCStream(zwc->zbc);
+    ZSTD_free(zwc, zwc->customMem);
     return 0;
 }
 
 
-ZWRAP_CCtx* ZWRAP_createCCtx(z_streamp strm)
+static ZWRAP_CCtx* ZWRAP_createCCtx(z_streamp strm)
 {
     ZWRAP_CCtx* zwc;
 
@@ -113,37 +120,36 @@ ZWRAP_CCtx* ZWRAP_createCCtx(z_streamp strm)
         if (zwc==NULL) return NULL;
         memset(zwc, 0, sizeof(ZWRAP_CCtx));
         memcpy(&zwc->allocFunc, strm, sizeof(z_stream));
-        { ZSTD_customMem ZWRAP_customMem = { ZWRAP_allocFunction, ZWRAP_freeFunction, &zwc->allocFunc };
-          memcpy(&zwc->customMem, &ZWRAP_customMem, sizeof(ZSTD_customMem));
-        }
+        { ZSTD_customMem const ZWRAP_customMem = { ZWRAP_allocFunction, ZWRAP_freeFunction, &zwc->allocFunc };
+          zwc->customMem = ZWRAP_customMem; }
     } else {
-        zwc = (ZWRAP_CCtx*)defaultCustomMem.customAlloc(defaultCustomMem.opaque, sizeof(ZWRAP_CCtx));
+        zwc = (ZWRAP_CCtx*)calloc(1, sizeof(*zwc));
         if (zwc==NULL) return NULL;
-        memset(zwc, 0, sizeof(ZWRAP_CCtx));
-        memcpy(&zwc->customMem, &defaultCustomMem, sizeof(ZSTD_customMem));
     }
 
     return zwc;
 }
 
 
-int ZWRAP_initializeCStream(ZWRAP_CCtx* zwc, const void* dict, size_t dictSize, unsigned long long pledgedSrcSize)
+static int ZWRAP_initializeCStream(ZWRAP_CCtx* zwc, const void* dict, size_t dictSize, unsigned long long pledgedSrcSize)
 {
     LOG_WRAPPERC("- ZWRAP_initializeCStream=%p\n", zwc);
     if (zwc == NULL || zwc->zbc == NULL) return Z_STREAM_ERROR;
 
     if (!pledgedSrcSize) pledgedSrcSize = zwc->pledgedSrcSize;
-    { ZSTD_parameters const params = ZSTD_getParams(zwc->compressionLevel, pledgedSrcSize, dictSize);
-      size_t errorCode;
-      LOG_WRAPPERC("pledgedSrcSize=%d windowLog=%d chainLog=%d hashLog=%d searchLog=%d searchLength=%d strategy=%d\n", (int)pledgedSrcSize, params.cParams.windowLog, params.cParams.chainLog, params.cParams.hashLog, params.cParams.searchLog, params.cParams.searchLength, params.cParams.strategy);
-      errorCode = ZSTD_initCStream_advanced(zwc->zbc, dict, dictSize, params, pledgedSrcSize);
-      if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR; }
+    {   ZSTD_parameters const params = ZSTD_getParams(zwc->compressionLevel, pledgedSrcSize, dictSize);
+        size_t initErr;
+        LOG_WRAPPERC("pledgedSrcSize=%d windowLog=%d chainLog=%d hashLog=%d searchLog=%d searchLength=%d strategy=%d\n",
+                    (int)pledgedSrcSize, params.cParams.windowLog, params.cParams.chainLog, params.cParams.hashLog, params.cParams.searchLog, params.cParams.searchLength, params.cParams.strategy);
+        initErr = ZSTD_initCStream_advanced(zwc->zbc, dict, dictSize, params, pledgedSrcSize);
+        if (ZSTD_isError(initErr)) return Z_STREAM_ERROR;
+    }
 
     return Z_OK;
 }
 
 
-int ZWRAPC_finishWithError(ZWRAP_CCtx* zwc, z_streamp strm, int error)
+static int ZWRAPC_finishWithError(ZWRAP_CCtx* zwc, z_streamp strm, int error)
 {
     LOG_WRAPPERC("- ZWRAPC_finishWithError=%d\n", error);
     if (zwc) ZWRAP_freeCCtx(zwc);
@@ -152,7 +158,7 @@ int ZWRAPC_finishWithError(ZWRAP_CCtx* zwc, z_streamp strm, int error)
 }
 
 
-int ZWRAPC_finishWithErrorMsg(z_streamp strm, char* message)
+static int ZWRAPC_finishWithErrorMsg(z_streamp strm, char* message)
 {
     ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
     strm->msg = message;
@@ -219,7 +225,7 @@ int ZWRAP_deflateReset_keepDict(z_streamp strm)
         return deflateReset(strm);
 
     { ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
-      if (zwc) { 
+      if (zwc) {
           zwc->streamEnd = 0;
           zwc->totalInBytes = 0;
       }
@@ -277,34 +283,36 @@ ZEXTERN int ZEXPORT z_deflate OF((z_streamp strm, int flush))
     ZWRAP_CCtx* zwc;
 
     if (!g_ZWRAP_useZSTDcompression) {
-        int res;
-        LOG_WRAPPERC("- deflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
-        res = deflate(strm, flush);
-        return res;
+        LOG_WRAPPERC("- deflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
+                    (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
+        return deflate(strm, flush);
     }
 
     zwc = (ZWRAP_CCtx*) strm->state;
     if (zwc == NULL) { LOG_WRAPPERC("zwc == NULL\n"); return Z_STREAM_ERROR; }
 
     if (zwc->zbc == NULL) {
-        int res;
         zwc->zbc = ZSTD_createCStream_advanced(zwc->customMem);
         if (zwc->zbc == NULL) return ZWRAPC_finishWithError(zwc, strm, 0);
-        res = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : 0);
-        if (res != Z_OK) return ZWRAPC_finishWithError(zwc, strm, res);
+        { int const initErr = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : 0);
+          if (initErr != Z_OK) return ZWRAPC_finishWithError(zwc, strm, initErr); }
         if (flush != Z_FINISH) zwc->comprState = ZWRAP_useReset;
     } else {
         if (zwc->totalInBytes == 0) {
             if (zwc->comprState == ZWRAP_useReset) {
-                size_t const errorCode = ZSTD_resetCStream(zwc->zbc, (flush == Z_FINISH) ? strm->avail_in : zwc->pledgedSrcSize);
-                if (ZSTD_isError(errorCode)) { LOG_WRAPPERC("ERROR: ZSTD_resetCStream errorCode=%s\n", ZSTD_getErrorName(errorCode)); return ZWRAPC_finishWithError(zwc, strm, 0); }
+                size_t const resetErr = ZSTD_resetCStream(zwc->zbc, (flush == Z_FINISH) ? strm->avail_in : zwc->pledgedSrcSize);
+                if (ZSTD_isError(resetErr)) {
+                    LOG_WRAPPERC("ERROR: ZSTD_resetCStream errorCode=%s\n",
+                                ZSTD_getErrorName(resetErr));
+                    return ZWRAPC_finishWithError(zwc, strm, 0);
+                }
             } else {
-                int res = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : 0);
+                int const res = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : 0);
                 if (res != Z_OK) return ZWRAPC_finishWithError(zwc, strm, res);
                 if (flush != Z_FINISH) zwc->comprState = ZWRAP_useReset;
             }
-        }
-    }
+        }  /* (zwc->totalInBytes == 0) */
+    }  /* ! (zwc->zbc == NULL) */
 
     LOG_WRAPPERC("- deflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
     if (strm->avail_in > 0) {
@@ -314,9 +322,9 @@ ZEXTERN int ZEXPORT z_deflate OF((z_streamp strm, int flush))
         zwc->outBuffer.dst = strm->next_out;
         zwc->outBuffer.size = strm->avail_out;
         zwc->outBuffer.pos = 0;
-        { size_t const errorCode = ZSTD_compressStream(zwc->zbc, &zwc->outBuffer, &zwc->inBuffer);
+        { size_t const cErr = ZSTD_compressStream(zwc->zbc, &zwc->outBuffer, &zwc->inBuffer);
           LOG_WRAPPERC("deflate ZSTD_compressStream srcSize=%d dstCapacity=%d\n", (int)zwc->inBuffer.size, (int)zwc->outBuffer.size);
-          if (ZSTD_isError(errorCode)) return ZWRAPC_finishWithError(zwc, strm, 0);
+          if (ZSTD_isError(cErr)) return ZWRAPC_finishWithError(zwc, strm, 0);
         }
         strm->next_out += zwc->outBuffer.pos;
         strm->total_out += zwc->outBuffer.pos;
@@ -346,8 +354,12 @@ ZEXTERN int ZEXPORT z_deflate OF((z_streamp strm, int flush))
         strm->next_out += zwc->outBuffer.pos;
         strm->total_out += zwc->outBuffer.pos;
         strm->avail_out -= zwc->outBuffer.pos;
-        if (bytesLeft == 0) { zwc->streamEnd = 1; LOG_WRAPPERC("Z_STREAM_END2 strm->total_in=%d strm->avail_out=%d strm->total_out=%d\n", (int)strm->total_in, (int)strm->avail_out, (int)strm->total_out); return Z_STREAM_END; }
-    }
+        if (bytesLeft == 0) {
+            zwc->streamEnd = 1;
+            LOG_WRAPPERC("Z_STREAM_END2 strm->total_in=%d strm->avail_out=%d strm->total_out=%d\n",
+                        (int)strm->total_in, (int)strm->avail_out, (int)strm->total_out);
+            return Z_STREAM_END;
+    }   }
     else
     if (flush == Z_SYNC_FLUSH || flush == Z_PARTIAL_FLUSH) {
         size_t bytesLeft;
@@ -410,12 +422,13 @@ ZEXTERN int ZEXPORT z_deflateParams OF((z_streamp strm,
 
 
 
-/* *** Decompression *** */
+/* ===   Decompression   === */
+
 typedef enum { ZWRAP_ZLIB_STREAM, ZWRAP_ZSTD_STREAM, ZWRAP_UNKNOWN_STREAM } ZWRAP_stream_type;
 
 typedef struct {
     ZSTD_DStream* zbd;
-    char headerBuf[16]; /* should be equal or bigger than ZSTD_frameHeaderSize_min */
+    char headerBuf[16];   /* must be >= ZSTD_frameHeaderSize_min */
     int errorCount;
     unsigned long long totalInBytes; /* we need it as strm->total_in can be reset by user */
     ZWRAP_state_t decompState;
@@ -427,72 +440,66 @@ typedef struct {
     char *version;
     int windowBits;
     ZSTD_customMem customMem;
-    z_stream allocFunc; /* copy of zalloc, zfree, opaque */
+    z_stream allocFunc; /* just to copy zalloc, zfree, opaque */
 } ZWRAP_DCtx;
 
 
-int ZWRAP_isUsingZSTDdecompression(z_streamp strm)
-{
-    if (strm == NULL) return 0;
-    return (strm->reserved == ZWRAP_ZSTD_STREAM);
-}
-
-
-void ZWRAP_initDCtx(ZWRAP_DCtx* zwd)
+static void ZWRAP_initDCtx(ZWRAP_DCtx* zwd)
 {
     zwd->errorCount = 0;
     zwd->outBuffer.pos = 0;
     zwd->outBuffer.size = 0;
 }
 
-
-ZWRAP_DCtx* ZWRAP_createDCtx(z_streamp strm)
+static ZWRAP_DCtx* ZWRAP_createDCtx(z_streamp strm)
 {
     ZWRAP_DCtx* zwd;
+    MEM_STATIC_ASSERT(sizeof(zwd->headerBuf) >= ZSTD_FRAMEHEADERSIZE_MIN);   /* check static buffer size condition */
 
     if (strm->zalloc && strm->zfree) {
         zwd = (ZWRAP_DCtx*)strm->zalloc(strm->opaque, 1, sizeof(ZWRAP_DCtx));
         if (zwd==NULL) return NULL;
         memset(zwd, 0, sizeof(ZWRAP_DCtx));
-        memcpy(&zwd->allocFunc, strm, sizeof(z_stream));
-        { ZSTD_customMem ZWRAP_customMem = { ZWRAP_allocFunction, ZWRAP_freeFunction, &zwd->allocFunc };
-          memcpy(&zwd->customMem, &ZWRAP_customMem, sizeof(ZSTD_customMem));
-        }
+        zwd->allocFunc = *strm;  /* just to copy zalloc, zfree & opaque */
+        { ZSTD_customMem const ZWRAP_customMem = { ZWRAP_allocFunction, ZWRAP_freeFunction, &zwd->allocFunc };
+          zwd->customMem = ZWRAP_customMem; }
     } else {
-        zwd = (ZWRAP_DCtx*)defaultCustomMem.customAlloc(defaultCustomMem.opaque, sizeof(ZWRAP_DCtx));
+        zwd = (ZWRAP_DCtx*)calloc(1, sizeof(*zwd));
         if (zwd==NULL) return NULL;
-        memset(zwd, 0, sizeof(ZWRAP_DCtx));
-        memcpy(&zwd->customMem, &defaultCustomMem, sizeof(ZSTD_customMem));
     }
 
-    MEM_STATIC_ASSERT(sizeof(zwd->headerBuf) >= ZSTD_FRAMEHEADERSIZE_MIN);   /* if compilation fails here, assertion is false */
     ZWRAP_initDCtx(zwd);
     return zwd;
 }
 
-
-size_t ZWRAP_freeDCtx(ZWRAP_DCtx* zwd)
+static size_t ZWRAP_freeDCtx(ZWRAP_DCtx* zwd)
 {
     if (zwd==NULL) return 0;   /* support free on null */
-    if (zwd->zbd) ZSTD_freeDStream(zwd->zbd);
-    if (zwd->version) zwd->customMem.customFree(zwd->customMem.opaque, zwd->version);
-    zwd->customMem.customFree(zwd->customMem.opaque, zwd);
+    ZSTD_freeDStream(zwd->zbd);
+    ZSTD_free(zwd->version, zwd->customMem);
+    ZSTD_free(zwd, zwd->customMem);
     return 0;
 }
 
 
-int ZWRAPD_finishWithError(ZWRAP_DCtx* zwd, z_streamp strm, int error)
+int ZWRAP_isUsingZSTDdecompression(z_streamp strm)
+{
+    if (strm == NULL) return 0;
+    return (strm->reserved == ZWRAP_ZSTD_STREAM);
+}
+
+
+static int ZWRAPD_finishWithError(ZWRAP_DCtx* zwd, z_streamp strm, int error)
 {
     LOG_WRAPPERD("- ZWRAPD_finishWithError=%d\n", error);
-    if (zwd) ZWRAP_freeDCtx(zwd);
-    if (strm) strm->state = NULL;
+    ZWRAP_freeDCtx(zwd);
+    strm->state = NULL;
     return (error) ? error : Z_STREAM_ERROR;
 }
 
-
-int ZWRAPD_finishWithErrorMsg(z_streamp strm, char* message)
+static int ZWRAPD_finishWithErrorMsg(z_streamp strm, char* message)
 {
-    ZWRAP_DCtx* zwd = (ZWRAP_DCtx*) strm->state;
+    ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
     strm->msg = message;
     if (zwd == NULL) return Z_STREAM_ERROR;
 
@@ -504,26 +511,25 @@ ZEXTERN int ZEXPORT z_inflateInit_ OF((z_streamp strm,
                                      const char *version, int stream_size))
 {
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB) {
-        strm->reserved = ZWRAP_ZLIB_STREAM; /* mark as zlib stream */
+        strm->reserved = ZWRAP_ZLIB_STREAM;
         return inflateInit(strm);
     }
 
-    {
-    ZWRAP_DCtx* zwd = ZWRAP_createDCtx(strm);
-    LOG_WRAPPERD("- inflateInit\n");
-    if (zwd == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);
+    {   ZWRAP_DCtx* const zwd = ZWRAP_createDCtx(strm);
+        LOG_WRAPPERD("- inflateInit\n");
+        if (zwd == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);
 
-    zwd->version = zwd->customMem.customAlloc(zwd->customMem.opaque, strlen(version) + 1);
-    if (zwd->version == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);
-    strcpy(zwd->version, version);
+        zwd->version = ZSTD_malloc(strlen(version)+1, zwd->customMem);
+        if (zwd->version == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);
+        strcpy(zwd->version, version);
 
-    zwd->stream_size = stream_size;
-    zwd->totalInBytes = 0;
-    strm->state = (struct internal_state*) zwd; /* use state which in not used by user */
-    strm->total_in = 0;
-    strm->total_out = 0;
-    strm->reserved = ZWRAP_UNKNOWN_STREAM; /* mark as unknown steam */
-    strm->adler = 0;
+        zwd->stream_size = stream_size;
+        zwd->totalInBytes = 0;
+        strm->state = (struct internal_state*) zwd;
+        strm->total_in = 0;
+        strm->total_out = 0;
+        strm->reserved = ZWRAP_UNKNOWN_STREAM;
+        strm->adler = 0;
     }
 
     return Z_OK;
@@ -537,15 +543,14 @@ ZEXTERN int ZEXPORT z_inflateInit2_ OF((z_streamp strm, int  windowBits,
         return inflateInit2_(strm, windowBits, version, stream_size);
     }
 
-    {
-    int ret = z_inflateInit_ (strm, version, stream_size);
-    LOG_WRAPPERD("- inflateInit2 windowBits=%d\n", windowBits);
-    if (ret == Z_OK) {
-        ZWRAP_DCtx* zwd = (ZWRAP_DCtx*)strm->state;
-        if (zwd == NULL) return Z_STREAM_ERROR;
-        zwd->windowBits = windowBits;
-    }
-    return ret;
+    {   int const ret = z_inflateInit_ (strm, version, stream_size);
+        LOG_WRAPPERD("- inflateInit2 windowBits=%d\n", windowBits);
+        if (ret == Z_OK) {
+            ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*)strm->state;
+            if (zwd == NULL) return Z_STREAM_ERROR;
+            zwd->windowBits = windowBits;
+        }
+        return ret;
     }
 }
 
@@ -555,7 +560,7 @@ int ZWRAP_inflateReset_keepDict(z_streamp strm)
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
         return inflateReset(strm);
 
-    {   ZWRAP_DCtx* zwd = (ZWRAP_DCtx*) strm->state;
+    {   ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
         if (zwd == NULL) return Z_STREAM_ERROR;
         ZWRAP_initDCtx(zwd);
         zwd->decompState = ZWRAP_useReset;
@@ -574,10 +579,10 @@ ZEXTERN int ZEXPORT z_inflateReset OF((z_streamp strm))
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
         return inflateReset(strm);
 
-    { int ret = ZWRAP_inflateReset_keepDict(strm);
+    { int const ret = ZWRAP_inflateReset_keepDict(strm);
       if (ret != Z_OK) return ret; }
 
-    { ZWRAP_DCtx* zwd = (ZWRAP_DCtx*) strm->state;
+    { ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
       if (zwd == NULL) return Z_STREAM_ERROR;
       zwd->decompState = ZWRAP_useInit; }
 
@@ -592,9 +597,9 @@ ZEXTERN int ZEXPORT z_inflateReset2 OF((z_streamp strm,
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
         return inflateReset2(strm, windowBits);
 
-    {   int ret = z_inflateReset (strm);
+    {   int const ret = z_inflateReset (strm);
         if (ret == Z_OK) {
-            ZWRAP_DCtx* zwd = (ZWRAP_DCtx*)strm->state;
+            ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*)strm->state;
             if (zwd == NULL) return Z_STREAM_ERROR;
             zwd->windowBits = windowBits;
         }
@@ -612,11 +617,10 @@ ZEXTERN int ZEXPORT z_inflateSetDictionary OF((z_streamp strm,
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
         return inflateSetDictionary(strm, dictionary, dictLength);
 
-    {   size_t errorCode;
-        ZWRAP_DCtx* zwd = (ZWRAP_DCtx*) strm->state;
+    {   ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
         if (zwd == NULL || zwd->zbd == NULL) return Z_STREAM_ERROR;
-        errorCode = ZSTD_initDStream_usingDict(zwd->zbd, dictionary, dictLength);
-        if (ZSTD_isError(errorCode)) return ZWRAPD_finishWithError(zwd, strm, 0);
+        { size_t const initErr = ZSTD_initDStream_usingDict(zwd->zbd, dictionary, dictLength);
+          if (ZSTD_isError(initErr)) return ZWRAPD_finishWithError(zwd, strm, 0); }
         zwd->decompState = ZWRAP_useReset;
 
         if (zwd->totalInBytes == ZSTD_HEADERSIZE) {
@@ -626,14 +630,14 @@ ZEXTERN int ZEXPORT z_inflateSetDictionary OF((z_streamp strm,
             zwd->outBuffer.dst = strm->next_out;
             zwd->outBuffer.size = 0;
             zwd->outBuffer.pos = 0;
-            errorCode = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
-            LOG_WRAPPERD("inflateSetDictionary ZSTD_decompressStream errorCode=%d srcSize=%d dstCapacity=%d\n", (int)errorCode, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
-            if (zwd->inBuffer.pos < zwd->outBuffer.size || ZSTD_isError(errorCode)) {
-                LOG_WRAPPERD("ERROR: ZSTD_decompressStream %s\n", ZSTD_getErrorName(errorCode));
-                return ZWRAPD_finishWithError(zwd, strm, 0);
-            }
-        }
-    }
+            {   size_t const errorCode = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
+                LOG_WRAPPERD("inflateSetDictionary ZSTD_decompressStream errorCode=%d srcSize=%d dstCapacity=%d\n",
+                             (int)errorCode, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
+                if (zwd->inBuffer.pos < zwd->outBuffer.size || ZSTD_isError(errorCode)) {
+                    LOG_WRAPPERD("ERROR: ZSTD_decompressStream %s\n",
+                                 ZSTD_getErrorName(errorCode));
+                    return ZWRAPD_finishWithError(zwd, strm, 0);
+    }   }   }   }
 
     return Z_OK;
 }
@@ -642,156 +646,175 @@ ZEXTERN int ZEXPORT z_inflateSetDictionary OF((z_streamp strm,
 ZEXTERN int ZEXPORT z_inflate OF((z_streamp strm, int flush))
 {
     ZWRAP_DCtx* zwd;
-    int res;
+
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved) {
-        LOG_WRAPPERD("- inflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
-        res = inflate(strm, flush);
-        LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
-        return res;
+        int const result = inflate(strm, flush);
+        LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
+                     (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, result);
+        return result;
     }
 
     if (strm->avail_in <= 0) return Z_OK;
 
-    {   size_t errorCode, srcSize;
-        zwd = (ZWRAP_DCtx*) strm->state;
-        LOG_WRAPPERD("- inflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
+    zwd = (ZWRAP_DCtx*) strm->state;
+    LOG_WRAPPERD("- inflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
+                 (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
 
-        if (zwd == NULL) return Z_STREAM_ERROR;
-        if (zwd->decompState == ZWRAP_streamEnd) return Z_STREAM_END;
-
-        if (zwd->totalInBytes < ZLIB_HEADERSIZE) {
-            if (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) {
-                if (MEM_readLE32(strm->next_in) != ZSTD_MAGICNUMBER) {
-                    if (zwd->windowBits)
-                        errorCode = inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size);
-                    else
-                        errorCode = inflateInit_(strm, zwd->version, zwd->stream_size);
-
-                    strm->reserved = ZWRAP_ZLIB_STREAM; /* mark as zlib stream */
-                    errorCode = ZWRAP_freeDCtx(zwd);
-                    if (ZSTD_isError(errorCode)) goto error;
-
-                    if (flush == Z_INFLATE_SYNC) res = inflateSync(strm);
-                    else res = inflate(strm, flush);
-                    LOG_WRAPPERD("- inflate3 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
-                    return res;
-                }
-            } else {
-                srcSize = MIN(strm->avail_in, ZLIB_HEADERSIZE - zwd->totalInBytes);
-                memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
-                strm->total_in += srcSize;
-                zwd->totalInBytes += srcSize;
-                strm->next_in += srcSize;
-                strm->avail_in -= srcSize;
-                if (zwd->totalInBytes < ZLIB_HEADERSIZE) return Z_OK;
-
-                if (MEM_readLE32(zwd->headerBuf) != ZSTD_MAGICNUMBER) {
-                    z_stream strm2;
-                    strm2.next_in = strm->next_in;
-                    strm2.avail_in = strm->avail_in;
-                    strm2.next_out = strm->next_out;
-                    strm2.avail_out = strm->avail_out;
-
-                    if (zwd->windowBits)
-                        errorCode = inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size);
-                    else
-                        errorCode = inflateInit_(strm, zwd->version, zwd->stream_size);
-                    LOG_WRAPPERD("ZLIB inflateInit errorCode=%d\n", (int)errorCode);
-                    if (errorCode != Z_OK) return ZWRAPD_finishWithError(zwd, strm, (int)errorCode);
-
-                    /* inflate header */
-                    strm->next_in = (unsigned char*)zwd->headerBuf;
-                    strm->avail_in = ZLIB_HEADERSIZE;
-                    strm->avail_out = 0;
-                    errorCode = inflate(strm, Z_NO_FLUSH);
-                    LOG_WRAPPERD("ZLIB inflate errorCode=%d strm->avail_in=%d\n", (int)errorCode, (int)strm->avail_in);
-                    if (errorCode != Z_OK) return ZWRAPD_finishWithError(zwd, strm, (int)errorCode);
-                    if (strm->avail_in > 0) goto error;
-
-                    strm->next_in = strm2.next_in;
-                    strm->avail_in = strm2.avail_in;
-                    strm->next_out = strm2.next_out;
-                    strm->avail_out = strm2.avail_out;
-
-                    strm->reserved = ZWRAP_ZLIB_STREAM; /* mark as zlib stream */
-                    errorCode = ZWRAP_freeDCtx(zwd);
-                    if (ZSTD_isError(errorCode)) goto error;
-
-                    if (flush == Z_INFLATE_SYNC) res = inflateSync(strm);
-                    else res = inflate(strm, flush);
-                    LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
-                    return res;
+    if (zwd == NULL) return Z_STREAM_ERROR;
+    if (zwd->decompState == ZWRAP_streamEnd) return Z_STREAM_END;
+
+    if (zwd->totalInBytes < ZLIB_HEADERSIZE) {
+        if (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) {
+            if (MEM_readLE32(strm->next_in) != ZSTD_MAGICNUMBER) {
+                {   int const initErr = (zwd->windowBits) ?
+                                inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size) :
+                                inflateInit_(strm, zwd->version, zwd->stream_size);
+                    LOG_WRAPPERD("ZLIB inflateInit errorCode=%d\n", initErr);
+                    if (initErr != Z_OK) return ZWRAPD_finishWithError(zwd, strm, initErr);
                 }
-            }
-        }
-
-        strm->reserved = ZWRAP_ZSTD_STREAM; /* mark as zstd steam */
 
-        if (flush == Z_INFLATE_SYNC) { strm->msg = "inflateSync is not supported!"; goto error; }
+                strm->reserved = ZWRAP_ZLIB_STREAM;
+                { size_t const freeErr = ZWRAP_freeDCtx(zwd);
+                  if (ZSTD_isError(freeErr)) goto error; }
+
+                {   int const result = (flush == Z_INFLATE_SYNC) ?
+                                        inflateSync(strm) :
+                                        inflate(strm, flush);
+                    LOG_WRAPPERD("- inflate3 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
+                                 (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
+                    return result;
+            }   }
+        } else {  /* ! (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) */
+            size_t const srcSize = MIN(strm->avail_in, ZLIB_HEADERSIZE - zwd->totalInBytes);
+            memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
+            strm->total_in += srcSize;
+            zwd->totalInBytes += srcSize;
+            strm->next_in += srcSize;
+            strm->avail_in -= srcSize;
+            if (zwd->totalInBytes < ZLIB_HEADERSIZE) return Z_OK;
+
+            if (MEM_readLE32(zwd->headerBuf) != ZSTD_MAGICNUMBER) {
+                z_stream strm2;
+                strm2.next_in = strm->next_in;
+                strm2.avail_in = strm->avail_in;
+                strm2.next_out = strm->next_out;
+                strm2.avail_out = strm->avail_out;
+
+                {   int const initErr = (zwd->windowBits) ?
+                                inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size) :
+                                inflateInit_(strm, zwd->version, zwd->stream_size);
+                    LOG_WRAPPERD("ZLIB inflateInit errorCode=%d\n", initErr);
+                    if (initErr != Z_OK) return ZWRAPD_finishWithError(zwd, strm, initErr);
+                }
 
-        if (!zwd->zbd) {
-            zwd->zbd = ZSTD_createDStream_advanced(zwd->customMem);
-            if (zwd->zbd == NULL) { LOG_WRAPPERD("ERROR: ZSTD_createDStream_advanced\n"); goto error; }
-            zwd->decompState = ZWRAP_useInit;
-        }
+                /* inflate header */
+                strm->next_in = (unsigned char*)zwd->headerBuf;
+                strm->avail_in = ZLIB_HEADERSIZE;
+                strm->avail_out = 0;
+                {   int const dErr = inflate(strm, Z_NO_FLUSH);
+                    LOG_WRAPPERD("ZLIB inflate errorCode=%d strm->avail_in=%d\n",
+                                  dErr, (int)strm->avail_in);
+                    if (dErr != Z_OK)
+                        return ZWRAPD_finishWithError(zwd, strm, dErr);
+                }
+                if (strm->avail_in > 0) goto error;
+
+                strm->next_in = strm2.next_in;
+                strm->avail_in = strm2.avail_in;
+                strm->next_out = strm2.next_out;
+                strm->avail_out = strm2.avail_out;
+
+                strm->reserved = ZWRAP_ZLIB_STREAM; /* mark as zlib stream */
+                { size_t const freeErr = ZWRAP_freeDCtx(zwd);
+                  if (ZSTD_isError(freeErr)) goto error; }
+
+                {   int const result = (flush == Z_INFLATE_SYNC) ?
+                                       inflateSync(strm) :
+                                       inflate(strm, flush);
+                    LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
+                                 (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
+                    return result;
+        }   }   }  /* if ! (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) */
+    }  /* (zwd->totalInBytes < ZLIB_HEADERSIZE) */
+
+    strm->reserved = ZWRAP_ZSTD_STREAM; /* mark as zstd steam */
+
+    if (flush == Z_INFLATE_SYNC) { strm->msg = "inflateSync is not supported!"; goto error; }
+
+    if (!zwd->zbd) {
+        zwd->zbd = ZSTD_createDStream_advanced(zwd->customMem);
+        if (zwd->zbd == NULL) { LOG_WRAPPERD("ERROR: ZSTD_createDStream_advanced\n"); goto error; }
+        zwd->decompState = ZWRAP_useInit;
+    }
 
-        if (zwd->totalInBytes < ZSTD_HEADERSIZE)
-        {
-            if (zwd->totalInBytes == 0 && strm->avail_in >= ZSTD_HEADERSIZE) {
-                if (zwd->decompState == ZWRAP_useInit) {
-                    errorCode = ZSTD_initDStream(zwd->zbd);
-                    if (ZSTD_isError(errorCode)) { LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n", ZSTD_getErrorName(errorCode)); goto error; }
-                } else {
-                    errorCode = ZSTD_resetDStream(zwd->zbd);
-                    if (ZSTD_isError(errorCode)) goto error;
+    if (zwd->totalInBytes < ZSTD_HEADERSIZE) {
+        if (zwd->totalInBytes == 0 && strm->avail_in >= ZSTD_HEADERSIZE) {
+            if (zwd->decompState == ZWRAP_useInit) {
+                size_t const initErr = ZSTD_initDStream(zwd->zbd);
+                if (ZSTD_isError(initErr)) {
+                    LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n",
+                                 ZSTD_getErrorName(initErr));
+                    goto error;
                 }
             } else {
-                srcSize = MIN(strm->avail_in, ZSTD_HEADERSIZE - zwd->totalInBytes);
-                memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
-                strm->total_in += srcSize;
-                zwd->totalInBytes += srcSize;
-                strm->next_in += srcSize;
-                strm->avail_in -= srcSize;
-                if (zwd->totalInBytes < ZSTD_HEADERSIZE) return Z_OK;
-
-                if (zwd->decompState == ZWRAP_useInit) {
-                    errorCode = ZSTD_initDStream(zwd->zbd);
-                    if (ZSTD_isError(errorCode)) { LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n", ZSTD_getErrorName(errorCode)); goto error; }
-                } else {
-                    errorCode = ZSTD_resetDStream(zwd->zbd);
-                    if (ZSTD_isError(errorCode)) goto error;
-                }
-
-                zwd->inBuffer.src = zwd->headerBuf;
-                zwd->inBuffer.size = ZSTD_HEADERSIZE;
-                zwd->inBuffer.pos = 0;
-                zwd->outBuffer.dst = strm->next_out;
-                zwd->outBuffer.size = 0;
-                zwd->outBuffer.pos = 0;
-                errorCode = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
-                LOG_WRAPPERD("inflate ZSTD_decompressStream1 errorCode=%d srcSize=%d dstCapacity=%d\n", (int)errorCode, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
-                if (ZSTD_isError(errorCode)) {
-                    LOG_WRAPPERD("ERROR: ZSTD_decompressStream1 %s\n", ZSTD_getErrorName(errorCode));
+                size_t const resetErr = ZSTD_resetDStream(zwd->zbd);
+                if (ZSTD_isError(resetErr)) goto error;
+            }
+        } else {
+            size_t const srcSize = MIN(strm->avail_in, ZSTD_HEADERSIZE - zwd->totalInBytes);
+            memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
+            strm->total_in += srcSize;
+            zwd->totalInBytes += srcSize;
+            strm->next_in += srcSize;
+            strm->avail_in -= srcSize;
+            if (zwd->totalInBytes < ZSTD_HEADERSIZE) return Z_OK;
+
+            if (zwd->decompState == ZWRAP_useInit) {
+                size_t const initErr = ZSTD_initDStream(zwd->zbd);
+                if (ZSTD_isError(initErr)) {
+                    LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n",
+                                ZSTD_getErrorName(initErr));
                     goto error;
                 }
-                if (zwd->inBuffer.pos != zwd->inBuffer.size) goto error; /* not consumed */
+            } else {
+                size_t const resetErr = ZSTD_resetDStream(zwd->zbd);
+                if (ZSTD_isError(resetErr)) goto error;
             }
+
+            zwd->inBuffer.src = zwd->headerBuf;
+            zwd->inBuffer.size = ZSTD_HEADERSIZE;
+            zwd->inBuffer.pos = 0;
+            zwd->outBuffer.dst = strm->next_out;
+            zwd->outBuffer.size = 0;
+            zwd->outBuffer.pos = 0;
+            {   size_t const dErr = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
+                LOG_WRAPPERD("inflate ZSTD_decompressStream1 errorCode=%d srcSize=%d dstCapacity=%d\n",
+                            (int)dErr, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
+                if (ZSTD_isError(dErr)) {
+                    LOG_WRAPPERD("ERROR: ZSTD_decompressStream1 %s\n", ZSTD_getErrorName(dErr));
+                    goto error;
+            }   }
+            if (zwd->inBuffer.pos != zwd->inBuffer.size) goto error; /* not consumed */
         }
+    }   /* (zwd->totalInBytes < ZSTD_HEADERSIZE) */
 
-        zwd->inBuffer.src = strm->next_in;
-        zwd->inBuffer.size = strm->avail_in;
-        zwd->inBuffer.pos = 0;
-        zwd->outBuffer.dst = strm->next_out;
-        zwd->outBuffer.size = strm->avail_out;
-        zwd->outBuffer.pos = 0;
-        errorCode = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
-        LOG_WRAPPERD("inflate ZSTD_decompressStream2 errorCode=%d srcSize=%d dstCapacity=%d\n", (int)errorCode, (int)strm->avail_in, (int)strm->avail_out);
-        if (ZSTD_isError(errorCode)) {
+    zwd->inBuffer.src = strm->next_in;
+    zwd->inBuffer.size = strm->avail_in;
+    zwd->inBuffer.pos = 0;
+    zwd->outBuffer.dst = strm->next_out;
+    zwd->outBuffer.size = strm->avail_out;
+    zwd->outBuffer.pos = 0;
+    {   size_t const dErr = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
+        LOG_WRAPPERD("inflate ZSTD_decompressStream2 errorCode=%d srcSize=%d dstCapacity=%d\n",
+                    (int)dErr, (int)strm->avail_in, (int)strm->avail_out);
+        if (ZSTD_isError(dErr)) {
             zwd->errorCount++;
-            LOG_WRAPPERD("ERROR: ZSTD_decompressStream2 %s zwd->errorCount=%d\n", ZSTD_getErrorName(errorCode), zwd->errorCount);
+            LOG_WRAPPERD("ERROR: ZSTD_decompressStream2 %s zwd->errorCount=%d\n",
+                        ZSTD_getErrorName(dErr), zwd->errorCount);
             if (zwd->errorCount<=1) return Z_NEED_DICT; else goto error;
         }
-        LOG_WRAPPERD("inflate inBuffer.pos=%d inBuffer.size=%d outBuffer.pos=%d outBuffer.size=%d o\n", (int)zwd->inBuffer.pos, (int)zwd->inBuffer.size, (int)zwd->outBuffer.pos, (int)zwd->outBuffer.size);
+        LOG_WRAPPERD("inflate inBuffer.pos=%d inBuffer.size=%d outBuffer.pos=%d outBuffer.size=%d o\n",
+                    (int)zwd->inBuffer.pos, (int)zwd->inBuffer.size, (int)zwd->outBuffer.pos, (int)zwd->outBuffer.size);
         strm->next_out += zwd->outBuffer.pos;
         strm->total_out += zwd->outBuffer.pos;
         strm->avail_out -= zwd->outBuffer.pos;
@@ -799,13 +822,16 @@ ZEXTERN int ZEXPORT z_inflate OF((z_streamp strm, int flush))
         zwd->totalInBytes += zwd->inBuffer.pos;
         strm->next_in += zwd->inBuffer.pos;
         strm->avail_in -= zwd->inBuffer.pos;
-        if (errorCode == 0) {
-            LOG_WRAPPERD("inflate Z_STREAM_END1 avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
+        if (dErr == 0) {
+            LOG_WRAPPERD("inflate Z_STREAM_END1 avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
+                        (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
             zwd->decompState = ZWRAP_streamEnd;
             return Z_STREAM_END;
         }
-    }
-    LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, Z_OK);
+    }  /* dErr lifetime */
+
+    LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
+                (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, Z_OK);
     return Z_OK;
 
 error:
@@ -818,13 +844,13 @@ ZEXTERN int ZEXPORT z_inflateEnd OF((z_streamp strm))
     if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
         return inflateEnd(strm);
 
-    LOG_WRAPPERD("- inflateEnd total_in=%d total_out=%d\n", (int)(strm->total_in), (int)(strm->total_out));
-    {   size_t errorCode;
-        ZWRAP_DCtx* zwd = (ZWRAP_DCtx*) strm->state;
+    LOG_WRAPPERD("- inflateEnd total_in=%d total_out=%d\n",
+                (int)(strm->total_in), (int)(strm->total_out));
+    {   ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
         if (zwd == NULL) return Z_OK;  /* structures are already freed */
+        { size_t const freeErr = ZWRAP_freeDCtx(zwd);
+          if (ZSTD_isError(freeErr)) return Z_STREAM_ERROR; }
         strm->state = NULL;
-        errorCode = ZWRAP_freeDCtx(zwd);
-        if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR;
     }
     return Z_OK;
 }
@@ -841,8 +867,6 @@ ZEXTERN int ZEXPORT z_inflateSync OF((z_streamp strm))
 
 
 
-
-
 /* Advanced compression functions */
 ZEXTERN int ZEXPORT z_deflateCopy OF((z_streamp dest,
                                     z_streamp source))
@@ -982,7 +1006,7 @@ ZEXTERN uLong ZEXPORT z_zlibCompileFlags OF((void)) { return zlibCompileFlags();
 
 
 
-                        /* utility functions */
+                    /* ===   utility functions  === */
 #ifndef Z_SOLO
 
 ZEXTERN int ZEXPORT z_compress OF((Bytef *dest,   uLongf *destLen,
@@ -991,11 +1015,14 @@ ZEXTERN int ZEXPORT z_compress OF((Bytef *dest,   uLongf *destLen,
     if (!g_ZWRAP_useZSTDcompression)
         return compress(dest, destLen, source, sourceLen);
 
-    { size_t dstCapacity = *destLen;
-      size_t const errorCode = ZSTD_compress(dest, dstCapacity, source, sourceLen, ZWRAP_DEFAULT_CLEVEL);
-      LOG_WRAPPERD("z_compress sourceLen=%d dstCapacity=%d\n", (int)sourceLen, (int)dstCapacity);
-      if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR;
-      *destLen = errorCode;
+    {   size_t dstCapacity = *destLen;
+        size_t const cSize = ZSTD_compress(dest, dstCapacity,
+                                           source, sourceLen,
+                                           ZWRAP_DEFAULT_CLEVEL);
+        LOG_WRAPPERD("z_compress sourceLen=%d dstCapacity=%d\n",
+                    (int)sourceLen, (int)dstCapacity);
+        if (ZSTD_isError(cSize)) return Z_STREAM_ERROR;
+        *destLen = cSize;
     }
     return Z_OK;
 }
@@ -1009,9 +1036,9 @@ ZEXTERN int ZEXPORT z_compress2 OF((Bytef *dest,   uLongf *destLen,
         return compress2(dest, destLen, source, sourceLen, level);
 
     { size_t dstCapacity = *destLen;
-      size_t const errorCode = ZSTD_compress(dest, dstCapacity, source, sourceLen, level);
-      if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR;
-      *destLen = errorCode;
+      size_t const cSize = ZSTD_compress(dest, dstCapacity, source, sourceLen, level);
+      if (ZSTD_isError(cSize)) return Z_STREAM_ERROR;
+      *destLen = cSize;
     }
     return Z_OK;
 }
@@ -1029,13 +1056,13 @@ ZEXTERN uLong ZEXPORT z_compressBound OF((uLong sourceLen))
 ZEXTERN int ZEXPORT z_uncompress OF((Bytef *dest,   uLongf *destLen,
                                    const Bytef *source, uLong sourceLen))
 {
-    if (sourceLen < 4 || MEM_readLE32(source) != ZSTD_MAGICNUMBER)
+    if (!ZSTD_isFrame(source, sourceLen))
         return uncompress(dest, destLen, source, sourceLen);
 
     { size_t dstCapacity = *destLen;
-      size_t const errorCode = ZSTD_decompress(dest, dstCapacity, source, sourceLen);
-      if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR;
-      *destLen = errorCode;
+      size_t const dSize = ZSTD_decompress(dest, dstCapacity, source, sourceLen);
+      if (ZSTD_isError(dSize)) return Z_STREAM_ERROR;
+      *destLen = dSize;
      }
     return Z_OK;
 }