Allow parameters to be modified from a separate file
diff --git a/contrib/long_distance_matching/Makefile b/contrib/long_distance_matching/Makefile
index 292ce85..b1fd3a1 100644
--- a/contrib/long_distance_matching/Makefile
+++ b/contrib/long_distance_matching/Makefile
@@ -25,16 +25,16 @@
default: all
-all: main-hash32 main-hash64
+all: main-64 main-integrated
-main-hash64: ldm_common.c ldm_hash64.c main.c
+main-64: ldm_common.c ldm_hash64.c main.c
$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
-main-hash32: ldm_common.c ldm_hash32.c main.c
+main-integrated: ldm_common.c ldm_hash32.c main.c
$(CC) $(CPPFLAGS) $(CFLAGS) $^ $(LDFLAGS) -o $@
clean:
@rm -f core *.o tmp* result* *.ldm *.ldm.dec \
- main-hash64 main-hash32
+ main-hash64 main-hash32 main-64 main-integrated
@echo Cleaning completed
diff --git a/contrib/long_distance_matching/ldm.c b/contrib/long_distance_matching/ldm.c
deleted file mode 100644
index fae35f9..0000000
--- a/contrib/long_distance_matching/ldm.c
+++ /dev/null
@@ -1,539 +0,0 @@
-#include <limits.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include "ldm.h"
-#include "ldm_hashtable.h"
-
-#define LDM_HASHTABLESIZE (1 << (LDM_MEMORY_USAGE))
-#define LDM_HASHTABLESIZE_U64 ((LDM_HASHTABLESIZE) >> 3)
-
-#define LDM_HASH_ENTRY_SIZE_LOG 3
-
-//#define HASH_ONLY_EVERY_LOG 7
-#define HASH_ONLY_EVERY_LOG (LDM_WINDOW_SIZE_LOG-((LDM_MEMORY_USAGE)-(LDM_HASH_ENTRY_SIZE_LOG)))
-
-#define HASH_ONLY_EVERY ((1 << HASH_ONLY_EVERY_LOG) - 1)
-
-
-#define COMPUTE_STATS
-#define OUTPUT_CONFIGURATION
-#define CHECKSUM_CHAR_OFFSET 10
-
-//#define RUN_CHECKS
-
-typedef U32 checksum_t;
-
-struct LDM_compressStats {
- U32 windowSizeLog, hashTableSizeLog;
- U32 numMatches;
- U64 totalMatchLength;
- U64 totalLiteralLength;
- U64 totalOffset;
-
- U32 minOffset, maxOffset;
-
- U32 offsetHistogram[32];
-};
-
-struct LDM_CCtx {
- U64 isize; /* Input size */
- U64 maxOSize; /* Maximum output size */
-
- const BYTE *ibase; /* Base of input */
- const BYTE *ip; /* Current input position */
- const BYTE *iend; /* End of input */
-
- // Maximum input position such that hashing at the position does not exceed
- // end of input.
- const BYTE *ihashLimit;
-
- // Maximum input position such that finding a match of at least the minimum
- // match length does not exceed end of input.
- const BYTE *imatchLimit;
-
- const BYTE *obase; /* Base of output */
- BYTE *op; /* Output */
-
- const BYTE *anchor; /* Anchor to start of current (match) block */
-
- LDM_compressStats stats; /* Compression statistics */
-
- LDM_hashTable *hashTable;
-
- const BYTE *lastPosHashed; /* Last position hashed */
- hash_t lastHash; /* Hash corresponding to lastPosHashed */
- checksum_t lastSum;
-
- const BYTE *nextIp; // TODO: this is redundant (ip + step)
- const BYTE *nextPosHashed;
- hash_t nextHash; /* Hash corresponding to nextPosHashed */
- checksum_t nextSum;
-
- unsigned step; // ip step, should be 1.
-
- const BYTE *lagIp;
- hash_t lagHash;
- checksum_t lagSum;
-
- // DEBUG
- const BYTE *DEBUG_setNextHash;
-};
-
-// TODO: This can be done more efficiently (but it is not that important as it
-// is only used for computing stats).
-static int intLog2(U32 x) {
- int ret = 0;
- while (x >>= 1) {
- ret++;
- }
- return ret;
-}
-
-void LDM_printCompressStats(const LDM_compressStats *stats) {
- int i = 0;
- printf("=====================\n");
- printf("Compression statistics\n");
- printf("Window size, hash table size (bytes): 2^%u, 2^%u\n",
- stats->windowSizeLog, stats->hashTableSizeLog);
- printf("num matches, total match length, %% matched: %u, %llu, %.3f\n",
- stats->numMatches,
- stats->totalMatchLength,
- 100.0 * (double)stats->totalMatchLength /
- (double)(stats->totalMatchLength + stats->totalLiteralLength));
- printf("avg match length: %.1f\n", ((double)stats->totalMatchLength) /
- (double)stats->numMatches);
- printf("avg literal length, total literalLength: %.1f, %llu\n",
- ((double)stats->totalLiteralLength) / (double)stats->numMatches,
- stats->totalLiteralLength);
- printf("avg offset length: %.1f\n",
- ((double)stats->totalOffset) / (double)stats->numMatches);
- printf("min offset, max offset: %u, %u\n",
- stats->minOffset, stats->maxOffset);
-
- printf("\n");
- printf("offset histogram: offset, num matches, %% of matches\n");
-
- for (; i <= intLog2(stats->maxOffset); i++) {
- printf("2^%*d: %10u %6.3f%%\n", 2, i,
- stats->offsetHistogram[i],
- 100.0 * (double) stats->offsetHistogram[i] /
- (double) stats->numMatches);
- }
- printf("\n");
- printf("=====================\n");
-}
-
-/**
- * Convert a sum computed from getChecksum to a hash value in the range
- * of the hash table.
- */
-static hash_t checksumToHash(U32 sum) {
- return HASH_hashU32(sum);
-}
-
-/**
- * Computes a 32-bit checksum based on rsync's checksum.
- *
- * a(k,l) = \sum_{i = k}^l x_i (mod M)
- * b(k,l) = \sum_{i = k}^l ((l - i + 1) * x_i) (mod M)
- * checksum(k,l) = a(k,l) + 2^{16} * b(k,l)
- */
-static checksum_t getChecksum(const BYTE *buf, U32 len) {
- U32 i;
- checksum_t s1, s2;
-
- s1 = s2 = 0;
- for (i = 0; i < (len - 4); i += 4) {
- s2 += (4 * (s1 + buf[i])) + (3 * buf[i + 1]) +
- (2 * buf[i + 2]) + (buf[i + 3]) +
- (10 * CHECKSUM_CHAR_OFFSET);
- s1 += buf[i] + buf[i + 1] + buf[i + 2] + buf[i + 3] +
- + (4 * CHECKSUM_CHAR_OFFSET);
-
- }
- for(; i < len; i++) {
- s1 += buf[i] + CHECKSUM_CHAR_OFFSET;
- s2 += s1;
- }
- return (s1 & 0xffff) + (s2 << 16);
-}
-
-/**
- * Update a checksum computed from getChecksum(data, len).
- *
- * The checksum can be updated along its ends as follows:
- * a(k+1, l+1) = (a(k,l) - x_k + x_{l+1}) (mod M)
- * b(k+1, l+1) = (b(k,l) - (l-k+1)*x_k + (a(k+1,l+1)) (mod M)
- *
- * Thus toRemove should correspond to data[0].
- */
-static checksum_t updateChecksum(checksum_t sum, U32 len,
- BYTE toRemove, BYTE toAdd) {
- U32 s1 = (sum & 0xffff) - toRemove + toAdd;
- U32 s2 = (sum >> 16) - ((toRemove + CHECKSUM_CHAR_OFFSET) * len) + s1;
-
- return (s1 & 0xffff) + (s2 << 16);
-}
-
-/**
- * Update cctx->nextSum, cctx->nextHash, and cctx->nextPosHashed
- * based on cctx->lastSum and cctx->lastPosHashed.
- *
- * This uses a rolling hash and requires that the last position hashed
- * corresponds to cctx->nextIp - step.
- */
-static void setNextHash(LDM_CCtx *cctx) {
-#ifdef RUN_CHECKS
- U32 check;
- if ((cctx->nextIp - cctx->ibase != 1) &&
- (cctx->nextIp - cctx->DEBUG_setNextHash != 1)) {
- printf("CHECK debug fail: %zu %zu\n", cctx->nextIp - cctx->ibase,
- cctx->DEBUG_setNextHash - cctx->ibase);
- }
-
- cctx->DEBUG_setNextHash = cctx->nextIp;
-#endif
-
- cctx->nextSum = updateChecksum(
- cctx->lastSum, LDM_HASH_LENGTH,
- cctx->lastPosHashed[0],
- cctx->lastPosHashed[LDM_HASH_LENGTH]);
- cctx->nextPosHashed = cctx->nextIp;
- cctx->nextHash = checksumToHash(cctx->nextSum);
-
-#if LDM_LAG
- if (cctx->ip - cctx->ibase > LDM_LAG) {
- cctx->lagSum = updateChecksum(
- cctx->lagSum, LDM_HASH_LENGTH,
- cctx->lagIp[0], cctx->lagIp[LDM_HASH_LENGTH]);
- cctx->lagIp++;
- cctx->lagHash = checksumToHash(cctx->lagSum);
- }
-#endif
-
-#ifdef RUN_CHECKS
- check = getChecksum(cctx->nextIp, LDM_HASH_LENGTH);
-
- if (check != cctx->nextSum) {
- printf("CHECK: setNextHash failed %u %u\n", check, cctx->nextSum);
- }
-
- if ((cctx->nextIp - cctx->lastPosHashed) != 1) {
- printf("setNextHash: nextIp != lastPosHashed + 1. %zu %zu %zu\n",
- cctx->nextIp - cctx->ibase, cctx->lastPosHashed - cctx->ibase,
- cctx->ip - cctx->ibase);
- }
-#endif
-}
-
-static void putHashOfCurrentPositionFromHash(
- LDM_CCtx *cctx, hash_t hash, U32 checksum) {
- // Hash only every HASH_ONLY_EVERY times, based on cctx->ip.
- // Note: this works only when cctx->step is 1.
- if (((cctx->ip - cctx->ibase) & HASH_ONLY_EVERY) == HASH_ONLY_EVERY) {
-#if LDM_LAG
- // Off by 1, but whatever
- if (cctx->lagIp - cctx->ibase > 0) {
- const LDM_hashEntry entry = { cctx->lagIp - cctx->ibase, cctx->lagSum };
- HASH_insert(cctx->hashTable, cctx->lagHash, entry);
- } else {
- const LDM_hashEntry entry = { cctx->ip - cctx->ibase, checksum };
- HASH_insert(cctx->hashTable, hash, entry);
- }
-#else
- const LDM_hashEntry entry = { cctx->ip - cctx->ibase, checksum };
- HASH_insert(cctx->hashTable, hash, entry);
-#endif
- }
-
- cctx->lastPosHashed = cctx->ip;
- cctx->lastHash = hash;
- cctx->lastSum = checksum;
-}
-
-/**
- * Copy over the cctx->lastHash, cctx->lastSum, and cctx->lastPosHashed
- * fields from the "next" fields.
- *
- * This requires that cctx->ip == cctx->nextPosHashed.
- */
-static void LDM_updateLastHashFromNextHash(LDM_CCtx *cctx) {
-#ifdef RUN_CHECKS
- if (cctx->ip != cctx->nextPosHashed) {
- printf("CHECK failed: updateLastHashFromNextHash %zu\n",
- cctx->ip - cctx->ibase);
- }
-#endif
- putHashOfCurrentPositionFromHash(cctx, cctx->nextHash, cctx->nextSum);
-}
-
-/**
- * Insert hash of the current position into the hash table.
- */
-static void LDM_putHashOfCurrentPosition(LDM_CCtx *cctx) {
- checksum_t sum = getChecksum(cctx->ip, LDM_HASH_LENGTH);
- hash_t hash = checksumToHash(sum);
-
-#ifdef RUN_CHECKS
- if (cctx->nextPosHashed != cctx->ip && (cctx->ip != cctx->ibase)) {
- printf("CHECK failed: putHashOfCurrentPosition %zu\n",
- cctx->ip - cctx->ibase);
- }
-#endif
-
- putHashOfCurrentPositionFromHash(cctx, hash, sum);
-}
-
-void LDM_initializeCCtx(LDM_CCtx *cctx,
- const void *src, size_t srcSize,
- void *dst, size_t maxDstSize) {
- cctx->isize = srcSize;
- cctx->maxOSize = maxDstSize;
-
- cctx->ibase = (const BYTE *)src;
- cctx->ip = cctx->ibase;
- cctx->iend = cctx->ibase + srcSize;
-
- cctx->ihashLimit = cctx->iend - LDM_HASH_LENGTH;
- cctx->imatchLimit = cctx->iend - LDM_MIN_MATCH_LENGTH;
-
- cctx->obase = (BYTE *)dst;
- cctx->op = (BYTE *)dst;
-
- cctx->anchor = cctx->ibase;
-
- memset(&(cctx->stats), 0, sizeof(cctx->stats));
- cctx->hashTable = HASH_createTable(LDM_HASHTABLESIZE_U64, cctx->ibase,
- LDM_MIN_MATCH_LENGTH, LDM_WINDOW_SIZE);
-
- cctx->stats.minOffset = UINT_MAX;
- cctx->stats.windowSizeLog = LDM_WINDOW_SIZE_LOG;
- cctx->stats.hashTableSizeLog = LDM_MEMORY_USAGE;
-
-
- cctx->lastPosHashed = NULL;
-
- cctx->step = 1; // Fixed to be 1 for now. Changing may break things.
- cctx->nextIp = cctx->ip + cctx->step;
- cctx->nextPosHashed = 0;
-
- cctx->DEBUG_setNextHash = 0;
-}
-
-void LDM_destroyCCtx(LDM_CCtx *cctx) {
- HASH_destroyTable(cctx->hashTable);
-}
-
-/**
- * Finds the "best" match.
- *
- * Returns 0 if successful and 1 otherwise (i.e. no match can be found
- * in the remaining input that is long enough).
- *
- * matchLength contains the forward length of the match.
- */
-static int LDM_findBestMatch(LDM_CCtx *cctx, const BYTE **match,
- U64 *matchLength, U64 *backwardMatchLength) {
-
- LDM_hashEntry *entry = NULL;
- cctx->nextIp = cctx->ip + cctx->step;
-
- while (entry == NULL) {
- hash_t h;
- checksum_t sum;
- setNextHash(cctx);
- h = cctx->nextHash;
- sum = cctx->nextSum;
- cctx->ip = cctx->nextIp;
- cctx->nextIp += cctx->step;
-
- if (cctx->ip > cctx->imatchLimit) {
- return 1;
- }
-
- entry = HASH_getBestEntry(cctx->hashTable, h, sum,
- cctx->ip, cctx->iend,
- cctx->anchor,
- matchLength, backwardMatchLength);
-
- if (entry != NULL) {
- *match = entry->offset + cctx->ibase;
- }
- putHashOfCurrentPositionFromHash(cctx, h, sum);
- }
- setNextHash(cctx);
- return 0;
-}
-
-void LDM_encodeLiteralLengthAndLiterals(
- LDM_CCtx *cctx, BYTE *pToken, const U64 literalLength) {
- /* Encode the literal length. */
- if (literalLength >= RUN_MASK) {
- int len = (int)literalLength - RUN_MASK;
- *pToken = (RUN_MASK << ML_BITS);
- for (; len >= 255; len -= 255) {
- *(cctx->op)++ = 255;
- }
- *(cctx->op)++ = (BYTE)len;
- } else {
- *pToken = (BYTE)(literalLength << ML_BITS);
- }
-
- /* Encode the literals. */
- memcpy(cctx->op, cctx->anchor, literalLength);
- cctx->op += literalLength;
-}
-
-void LDM_outputBlock(LDM_CCtx *cctx,
- const U64 literalLength,
- const U32 offset,
- const U64 matchLength) {
- BYTE *pToken = cctx->op++;
-
- /* Encode the literal length and literals. */
- LDM_encodeLiteralLengthAndLiterals(cctx, pToken, literalLength);
-
- /* Encode the offset. */
- MEM_write32(cctx->op, offset);
- cctx->op += LDM_OFFSET_SIZE;
-
- /* Encode the match length. */
- if (matchLength >= ML_MASK) {
- U64 matchLengthRemaining = matchLength;
- *pToken += ML_MASK;
- matchLengthRemaining -= ML_MASK;
- MEM_write32(cctx->op, 0xFFFFFFFF);
- while (matchLengthRemaining >= 4*0xFF) {
- cctx->op += 4;
- MEM_write32(cctx->op, 0xffffffff);
- matchLengthRemaining -= 4*0xFF;
- }
- cctx->op += matchLengthRemaining / 255;
- *(cctx->op)++ = (BYTE)(matchLengthRemaining % 255);
- } else {
- *pToken += (BYTE)(matchLength);
- }
-}
-
-// TODO: maxDstSize is unused. This function may seg fault when writing
-// beyond the size of dst, as it does not check maxDstSize. Writing to
-// a buffer and performing checks is a possible solution.
-//
-// This is based upon lz4.
-size_t LDM_compress(const void *src, size_t srcSize,
- void *dst, size_t maxDstSize) {
- LDM_CCtx cctx;
- const BYTE *match = NULL;
- U64 forwardMatchLength = 0;
- U64 backwardsMatchLength = 0;
-
- LDM_initializeCCtx(&cctx, src, srcSize, dst, maxDstSize);
- LDM_outputConfiguration();
-
- /* Hash the first position and put it into the hash table. */
- LDM_putHashOfCurrentPosition(&cctx);
-
-#if LDM_LAG
- cctx.lagIp = cctx.ip;
- cctx.lagHash = cctx.lastHash;
- cctx.lagSum = cctx.lastSum;
-#endif
- /**
- * Find a match.
- * If no more matches can be found (i.e. the length of the remaining input
- * is less than the minimum match length), then stop searching for matches
- * and encode the final literals.
- */
- while (LDM_findBestMatch(&cctx, &match, &forwardMatchLength,
- &backwardsMatchLength) == 0) {
-#ifdef COMPUTE_STATS
- cctx.stats.numMatches++;
-#endif
-
- cctx.ip -= backwardsMatchLength;
- match -= backwardsMatchLength;
-
- /**
- * Write current block (literals, literal length, match offset, match
- * length) and update pointers and hashes.
- */
- {
- const U32 literalLength = cctx.ip - cctx.anchor;
- const U32 offset = cctx.ip - match;
- const U32 matchLength = forwardMatchLength +
- backwardsMatchLength -
- LDM_MIN_MATCH_LENGTH;
-
- LDM_outputBlock(&cctx, literalLength, offset, matchLength);
-
-#ifdef COMPUTE_STATS
- cctx.stats.totalLiteralLength += literalLength;
- cctx.stats.totalOffset += offset;
- cctx.stats.totalMatchLength += matchLength + LDM_MIN_MATCH_LENGTH;
- cctx.stats.minOffset =
- offset < cctx.stats.minOffset ? offset : cctx.stats.minOffset;
- cctx.stats.maxOffset =
- offset > cctx.stats.maxOffset ? offset : cctx.stats.maxOffset;
- cctx.stats.offsetHistogram[(U32)intLog2(offset)]++;
-#endif
-
- // Move ip to end of block, inserting hashes at each position.
- cctx.nextIp = cctx.ip + cctx.step;
- while (cctx.ip < cctx.anchor + LDM_MIN_MATCH_LENGTH +
- matchLength + literalLength) {
- if (cctx.ip > cctx.lastPosHashed) {
- // TODO: Simplify.
- LDM_updateLastHashFromNextHash(&cctx);
- setNextHash(&cctx);
- }
- cctx.ip++;
- cctx.nextIp++;
- }
- }
-
- // Set start of next block to current input pointer.
- cctx.anchor = cctx.ip;
- LDM_updateLastHashFromNextHash(&cctx);
- }
-
- /* Encode the last literals (no more matches). */
- {
- const U32 lastRun = cctx.iend - cctx.anchor;
- BYTE *pToken = cctx.op++;
- LDM_encodeLiteralLengthAndLiterals(&cctx, pToken, lastRun);
- }
-
-#ifdef COMPUTE_STATS
- LDM_printCompressStats(&cctx.stats);
- HASH_outputTableOccupancy(cctx.hashTable);
-#endif
-
- {
- const size_t ret = cctx.op - cctx.obase;
- LDM_destroyCCtx(&cctx);
- return ret;
- }
-}
-
-void LDM_outputConfiguration(void) {
- printf("=====================\n");
- printf("Configuration\n");
- printf("LDM_WINDOW_SIZE_LOG: %d\n", LDM_WINDOW_SIZE_LOG);
- printf("LDM_MIN_MATCH_LENGTH, LDM_HASH_LENGTH: %d, %d\n",
- LDM_MIN_MATCH_LENGTH, LDM_HASH_LENGTH);
- printf("LDM_MEMORY_USAGE: %d\n", LDM_MEMORY_USAGE);
- printf("HASH_ONLY_EVERY_LOG: %d\n", HASH_ONLY_EVERY_LOG);
- printf("HASH_BUCKET_SIZE_LOG: %d\n", HASH_BUCKET_SIZE_LOG);
- printf("LDM_LAG %d\n", LDM_LAG);
- printf("=====================\n");
-}
-
-
-
-void LDM_test(const BYTE *src) {
- (void)src;
-}
-
diff --git a/contrib/long_distance_matching/ldm.h b/contrib/long_distance_matching/ldm.h
index f9ad383..b87a57b 100644
--- a/contrib/long_distance_matching/ldm.h
+++ b/contrib/long_distance_matching/ldm.h
@@ -2,6 +2,7 @@
#define LDM_H
#include "mem.h" // from /lib/common/mem.h
+#include "ldm_params.h"
// The number of bytes storing the compressed and decompressed size
// in the header.
@@ -18,35 +19,38 @@
#define LDM_OFFSET_SIZE 4
// =============================================================================
-// User parameters.
+// Modify parameters in ldm_params.h if "ldm_params.h" is included.
// =============================================================================
+#ifndef LDM_PARAMS_H
// Defines the size of the hash table.
// Note that this is not the number of buckets.
// Currently this should be less than WINDOW_SIZE_LOG + 4?
-#define LDM_MEMORY_USAGE 25
+ #define LDM_MEMORY_USAGE 25
// The number of entries in a hash bucket.
-#define HASH_BUCKET_SIZE_LOG 3 // The maximum is 4 for now.
+ #define HASH_BUCKET_SIZE_LOG 3 // The maximum is 4 for now.
// Defines the lag in inserting elements into the hash table.
-#define LDM_LAG 0
+ #define LDM_LAG 0
// The maximum window size.
-#define LDM_WINDOW_SIZE_LOG 28 // Max value is 30
-#define LDM_WINDOW_SIZE (1 << (LDM_WINDOW_SIZE_LOG))
+ #define LDM_WINDOW_SIZE_LOG 28 // Max value is 30
//These should be multiples of four (and perhaps set to the same value?).
-#define LDM_MIN_MATCH_LENGTH 64
-#define LDM_HASH_LENGTH 64
+ #define LDM_MIN_MATCH_LENGTH 64
-// Experimental.
-//#define TMP_EVICTION // Experiment with eviction policies.
-#define INSERT_BY_TAG // Insertion policy based on hash.
+ #define INSERT_BY_TAG 1 // Insertion policy based on hash.
-#define USE_CHECKSUM 1
+ #define USE_CHECKSUM 1
+#endif
// =============================================================================
+#define COMPUTE_STATS
+#define OUTPUT_CONFIGURATION
+
+#define LDM_WINDOW_SIZE (1 << (LDM_WINDOW_SIZE_LOG))
+#define LDM_HASH_LENGTH LDM_MIN_MATCH_LENGTH
typedef struct LDM_compressStats LDM_compressStats;
typedef struct LDM_CCtx LDM_CCtx;
@@ -164,6 +168,4 @@
*/
void LDM_outputConfiguration(void);
-void LDM_test(const BYTE *src);
-
#endif /* LDM_H */
diff --git a/contrib/long_distance_matching/ldm_common.c b/contrib/long_distance_matching/ldm_common.c
index 1953656..26b716a 100644
--- a/contrib/long_distance_matching/ldm_common.c
+++ b/contrib/long_distance_matching/ldm_common.c
@@ -70,7 +70,8 @@
dctx.ip += length;
dctx.op = cpy;
- //TODO : dynamic offset size
+ //TODO: dynamic offset size?
+ /* Encode the offset. */
offset = MEM_read32(dctx.ip);
dctx.ip += LDM_OFFSET_SIZE;
match = dctx.op - offset;
@@ -89,7 +90,7 @@
/* Copy match. */
cpy = dctx.op + length;
- // Inefficient for now.
+ // TODO: this can be made more efficient.
while (match < cpy - offset && dctx.op < dctx.oend) {
*(dctx.op)++ = *match++;
}
diff --git a/contrib/long_distance_matching/ldm_hash32.c b/contrib/long_distance_matching/ldm_hash32.c
index b80a5c0..94fa5e9 100644
--- a/contrib/long_distance_matching/ldm_hash32.c
+++ b/contrib/long_distance_matching/ldm_hash32.c
@@ -21,9 +21,7 @@
#define HASH_BUCKET_SIZE (1 << (HASH_BUCKET_SIZE_LOG))
#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-(LDM_HASH_ENTRY_SIZE_LOG)-(HASH_BUCKET_SIZE_LOG))
-#define COMPUTE_STATS
-#define OUTPUT_CONFIGURATION
-#define CHECKSUM_CHAR_OFFSET 1
+#define CHECKSUM_CHAR_OFFSET 10
// Take first match only.
//#define ZSTD_SKIP
@@ -779,8 +777,6 @@
LDM_updateLastHashFromNextHash(&cctx);
}
- // HASH_outputTableOffsetHistogram(&cctx);
-
/* Encode the last literals (no more matches). */
{
const U32 lastRun = cctx.iend - cctx.anchor;
@@ -815,9 +811,3 @@
-// TODO: implement and test hash function
-void LDM_test(const BYTE *src) {
- (void)src;
-}
-
-
diff --git a/contrib/long_distance_matching/ldm_hash64.c b/contrib/long_distance_matching/ldm_hash64.c
index e51ac57..884f7b7 100644
--- a/contrib/long_distance_matching/ldm_hash64.c
+++ b/contrib/long_distance_matching/ldm_hash64.c
@@ -24,8 +24,6 @@
#define HASH_BUCKET_SIZE (1 << (HASH_BUCKET_SIZE_LOG))
#define LDM_HASHLOG ((LDM_MEMORY_USAGE)-(LDM_HASH_ENTRY_SIZE_LOG)-(HASH_BUCKET_SIZE_LOG))
-#define COMPUTE_STATS
-#define OUTPUT_CONFIGURATION
#define HASH_CHAR_OFFSET 10
// Take first match only.
@@ -63,11 +61,6 @@
U64 TMP_hashCount[1 << HASH_ONLY_EVERY_LOG];
U64 TMP_totalHashCount;
-
- U64 TMP_totalInWindow;
- U64 TMP_totalInserts;
-
- U64 TMP_matchCount;
};
typedef struct LDM_hashTable LDM_hashTable;
@@ -328,91 +321,12 @@
return NULL;
}
-#ifdef TMP_EVICTION
-void HASH_insert(LDM_hashTable *table,
- const hash_t hash, const LDM_hashEntry entry,
- LDM_CCtx *cctx) {
- // Overwrite based on part of checksum.
- /*
- LDM_hashEntry *toOverwrite =
- getBucket(table, hash) + table->bucketOffsets[hash];
- const BYTE *pMatch = toOverwrite->offset + cctx->ibase;
- if (toOverwrite->offset != 0 &&
- cctx->ip - pMatch <= LDM_WINDOW_SIZE) {
- cctx->stats.TMP_totalInWindow++;
- }
-
- cctx->stats.TMP_totalInserts++;
- *(toOverwrite) = entry;
- */
-
- /*
- int i;
- LDM_hashEntry *bucket = getBucket(table, hash);
- for (i = 0; i < HASH_BUCKET_SIZE; i++) {
- if (bucket[i].checksum == entry.checksum) {
- bucket[i] = entry;
- cctx->stats.TMP_matchCount++;
- return;
- }
- }
- */
-
- // Find entry beyond window size, replace. Else, random.
- int i;
- LDM_hashEntry *bucket = getBucket(table, hash);
- for (i = 0; i < HASH_BUCKET_SIZE; i++) {
- if (cctx->ip - cctx->ibase - bucket[i].offset > LDM_WINDOW_SIZE) {
- bucket[i] = entry;
- return;
- }
- }
-
- i = rand() & (HASH_BUCKET_SIZE - 1);
- *(bucket + i) = entry;
-
-
- /**
- * Sliding buffer style pointer
- * Keep old entry as temporary. If the old entry is outside the window,
- * overwrite and we are done.
- *
- * Backwards (insert at x):
- * x, a, b b, c c c c, d d d d d d d d
- * x, d d d d d d d d, c c c c, b b, a
- *
- * Else, find something to evict.
- * If old entry has more ones, it takes
- * the next spot. <-- reversed order?
- *
- * If window size > LDM_WINDOW_SIZE,
- * overwrite,
- *
- * Insert forwards. If > tag, keep. Else evict.
- *
- */
-
-
- /*
- *(getBucket(table, hash) + table->bucketOffsets[hash]) = entry;
- table->bucketOffsets[hash]++;
- table->bucketOffsets[hash] &= HASH_BUCKET_SIZE - 1;
- */
-
-// U16 mask = entry.checksum & (HASH_BUCKET_SIZE - 1);
-// *(getBucket(table, hash) + mask) = entry;
-}
-
-#else
-
void HASH_insert(LDM_hashTable *table,
const hash_t hash, const LDM_hashEntry entry) {
*(getBucket(table, hash) + table->bucketOffsets[hash]) = entry;
table->bucketOffsets[hash]++;
table->bucketOffsets[hash] &= HASH_BUCKET_SIZE - 1;
}
-#endif // TMP_EVICTION
-
U32 HASH_getSize(const LDM_hashTable *table) {
return table->numBuckets;
@@ -489,7 +403,7 @@
(double) stats->numMatches);
}
printf("\n");
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
/*
printf("Lower bit distribution\n");
for (i = 0; i < (1 << HASH_ONLY_EVERY_LOG); i++) {
@@ -500,13 +414,6 @@
*/
#endif
-#ifdef TMP_EVICTION
- printf("Evicted something in window: %llu %6.3f\n",
- stats->TMP_totalInWindow,
- 100.0 * (double)stats->TMP_totalInWindow /
- (double)stats->TMP_totalInserts);
- printf("Match count: %llu\n", stats->TMP_matchCount);
-#endif
printf("=====================\n");
}
@@ -524,7 +431,7 @@
return (hash >> (64 - 32 - LDM_HASHLOG)) & 0xFFFFFFFF;
}
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
static U32 lowerBitsFromHfHash(U64 hash) {
// The number of bits used so far is LDM_HASHLOG + 32.
// So there are 32 - LDM_HASHLOG bits left.
@@ -611,7 +518,7 @@
cctx->lastPosHashed[LDM_HASH_LENGTH]);
cctx->nextPosHashed = cctx->nextIp;
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
{
U32 hashEveryMask = lowerBitsFromHfHash(cctx->nextHash);
cctx->stats.TMP_totalHashCount++;
@@ -648,7 +555,7 @@
// Note: this works only when cctx->step is 1.
#if LDM_LAG
if (cctx -> lagIp - cctx->ibase > 0) {
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
U32 hashEveryMask = lowerBitsFromHfHash(cctx->lagHash);
if (hashEveryMask == HASH_ONLY_EVERY) {
#else
@@ -663,14 +570,11 @@
const LDM_hashEntry entry = { cctx->lagIp - cctx->ibase };
# endif
-# ifdef TMP_EVICTION
- HASH_insert(cctx->hashTable, smallHash, entry, cctx);
-# else
HASH_insert(cctx->hashTable, smallHash, entry);
-# endif
}
} else {
-#ifdef INSERT_BY_TAG
+#endif // LDM_LAG
+#if INSERT_BY_TAG
U32 hashEveryMask = lowerBitsFromHfHash(hash);
if (hashEveryMask == HASH_ONLY_EVERY) {
#else
@@ -684,33 +588,9 @@
#else
const LDM_hashEntry entry = { cctx->ip - cctx->ibase };
#endif
-
-#ifdef TMP_EVICTION
- HASH_insert(cctx->hashTable, smallHash, entry, cctx);
-#else
HASH_insert(cctx->hashTable, smallHash, entry);
-#endif
}
- }
-#else
-#ifdef INSERT_BY_TAG
- U32 hashEveryMask = lowerBitsFromHfHash(hash);
- if (hashEveryMask == HASH_ONLY_EVERY) {
-#else
- if (((cctx->ip - cctx->ibase) & HASH_ONLY_EVERY) == HASH_ONLY_EVERY) {
-#endif
- U32 smallHash = getSmallHash(hash);
-#if USE_CHECKSUM
- U32 checksum = getChecksum(hash);
- const LDM_hashEntry entry = { cctx->ip - cctx->ibase, checksum };
-#else
- const LDM_hashEntry entry = { cctx->ip - cctx->ibase };
-#endif
-#ifdef TMP_EVICTION
- HASH_insert(cctx->hashTable, smallHash, entry, cctx);
-#else
- HASH_insert(cctx->hashTable, smallHash, entry);
-#endif
+#if LDM_LAG
}
#endif
@@ -812,7 +692,7 @@
U64 hash;
hash_t smallHash;
U32 checksum;
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
U32 hashEveryMask;
#endif
setNextHash(cctx);
@@ -820,7 +700,7 @@
hash = cctx->nextHash;
smallHash = getSmallHash(hash);
checksum = getChecksum(hash);
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
hashEveryMask = lowerBitsFromHfHash(hash);
#endif
@@ -830,7 +710,7 @@
if (cctx->ip > cctx->imatchLimit) {
return 1;
}
-#ifdef INSERT_BY_TAG
+#if INSERT_BY_TAG
if (hashEveryMask == HASH_ONLY_EVERY) {
entry = HASH_getBestEntry(cctx, smallHash, checksum,
@@ -923,10 +803,8 @@
/* Hash the first position and put it into the hash table. */
LDM_putHashOfCurrentPosition(&cctx);
-#if LDM_LAG
cctx.lagIp = cctx.ip;
cctx.lagHash = cctx.lastHash;
-#endif
/**
* Find a match.
* If no more matches can be found (i.e. the length of the remaining input
@@ -1018,28 +896,8 @@
printf("HASH_BUCKET_SIZE_LOG: %d\n", HASH_BUCKET_SIZE_LOG);
printf("LDM_LAG: %d\n", LDM_LAG);
printf("USE_CHECKSUM: %d\n", USE_CHECKSUM);
-#ifdef INSERT_BY_TAG
- printf("INSERT_BY_TAG: %d\n", 1);
-#else
- printf("INSERT_BY_TAG: %d\n", 0);
-#endif
+ printf("INSERT_BY_TAG: %d\n", INSERT_BY_TAG);
printf("HASH_CHAR_OFFSET: %d\n", HASH_CHAR_OFFSET);
printf("=====================\n");
}
-// TODO: implement and test hash function
-void LDM_test(const BYTE *src) {
- const U32 diff = 100;
- const BYTE *pCur = src + diff;
- U64 hash = getHash(pCur, LDM_HASH_LENGTH);
-
- for (; pCur < src + diff + 60; ++pCur) {
- U64 nextHash = getHash(pCur + 1, LDM_HASH_LENGTH);
- U64 updatedHash = updateHash(hash, LDM_HASH_LENGTH,
- pCur[0], pCur[LDM_HASH_LENGTH]);
- hash = nextHash;
- printf("%llu %llu\n", nextHash, updatedHash);
- }
-}
-
-
diff --git a/contrib/long_distance_matching/ldm_params.h b/contrib/long_distance_matching/ldm_params.h
new file mode 100644
index 0000000..0fcd30b
--- /dev/null
+++ b/contrib/long_distance_matching/ldm_params.h
@@ -0,0 +1,10 @@
+#ifndef LDM_PARAMS_H
+#define LDM_PARAMS_H
+#define LDM_MEMORY_USAGE 23
+#define HASH_BUCKET_SIZE_LOG 3
+#define LDM_LAG 0
+#define LDM_WINDOW_SIZE_LOG 28
+#define LDM_MIN_MATCH_LENGTH 64
+#define INSERT_BY_TAG 1
+#define USE_CHECKSUM 1
+#endif
diff --git a/contrib/long_distance_matching/main.c b/contrib/long_distance_matching/main.c
index cee5edb..bdd385c 100644
--- a/contrib/long_distance_matching/main.c
+++ b/contrib/long_distance_matching/main.c
@@ -12,7 +12,7 @@
#include "ldm.h"
#include "zstd.h"
-//#define DECOMPRESS_AND_VERIFY
+#define DECOMPRESS_AND_VERIFY
/* Compress file given by fname and output to oname.
* Returns 0 if successful, error code otherwise.
@@ -71,10 +71,6 @@
return 1;
}
-#ifdef TEST
- LDM_test((const BYTE *)src);
-#endif
-
gettimeofday(&tv1, NULL);
compressedSize = LDM_HEADER_SIZE +
@@ -111,7 +107,7 @@
return 0;
}
-#ifdef DECOMPRESS
+#ifdef DECOMPRESS_AND_VERIFY
/* Decompress file compressed using LDM_compress.
* The input file should have the LDM_HEADER followed by payload.
* Returns 0 if succesful, and an error code otherwise.
