Adding --long support for --patch-from (#1959)

* adding long support for patch-from

* adding refPrefix to dictionary_decompress

* adding refPrefix to dictionary_loader

* conversion nit

* triggering log mode on chainLog < fileLog and removing old threshold

* adding refPrefix to dictionary_round_trip

* adding docs

* adding enableldm + forceWindow test for dict

* separate patch-from logic into FIO_adjustParamsForPatchFromMode

* moving memLimit adjustment to outside ifdefs (need for decomp)

* removing refPrefix gate on dictionary_round_trip

* rebase on top of dev refPrefix change

* making sure refPrefx + ldm is < 1% of srcSize

* combining notes for patch-from

* moving memlimit logic inside fileio.c

* adding display for optimal parser and long mode trigger

* conversion nit

* fuzzer found heap-overflow fix

* another conversion nit

* moving FIO_adjustMemLimitForPatchFromMode outside ifndef

* making params immutable

* moving memLimit update before createDictBuffer call

* making maxSrcSize unsigned long long

* making dictSize and maxSrcSize params unsigned long long

* error on files larger than 4gb

* extend refPrefix test to include round trip

* conversion to size_t

* making sure ldm is at least 10x better

* removing break

* including zstd_compress_internal and removing redundant macros

* exposing ZSTD_cycleLog()

* using cycleLog instead of chainLog

* add some more docs about user optimizations

* formatting

lib/compress/zstd_compress_internal.h

@@ -166,6 +166,7 @@ typedef struct {
 typedef struct {
     ZSTD_window_t window;   /* State for the window round buffer management */
     ldmEntry_t* hashTable;
+    U32 loadedDictEnd;
     BYTE* bucketOffsets;    /* Next position in bucket to insert entry */
     U64 hashPower;          /* Used to compute the rolling hash.
                              * Depends on ldmParams.minMatchLength */
@@ -1051,5 +1052,8 @@ size_t ZSTD_writeLastEmptyBlock(void* dst, size_t dstCapacity);
  */
 size_t ZSTD_referenceExternalSequences(ZSTD_CCtx* cctx, rawSeq* seq, size_t nbSeq);
 
+/** ZSTD_cycleLog() :
+ *  condition for correct operation : hashLog > 1 */
+U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat);
 
 #endif /* ZSTD_COMPRESS_H */