[ldm] Make some functions shared

contrib/long_distance_matching/ldm.h

@@ -9,11 +9,15 @@
 #define LDM_DECOMPRESS_SIZE 8
 #define LDM_HEADER_SIZE ((LDM_COMPRESS_SIZE)+(LDM_DECOMPRESS_SIZE))
 
+// This should be a multiple of four.
+#define LDM_MIN_MATCH_LENGTH 8
+
 typedef U32 offset_t;
 typedef U32 hash_t;
 typedef struct LDM_hashEntry LDM_hashEntry;
 typedef struct LDM_compressStats LDM_compressStats;
 typedef struct LDM_CCtx LDM_CCtx;
+typedef struct LDM_DCtx LDM_DCtx;
 
 /**
  *  Compresses src into dst.
@@ -45,17 +49,78 @@ typedef struct LDM_CCtx LDM_CCtx;
 size_t LDM_compress(const void *src, size_t srcSize,
                     void *dst, size_t maxDstSize);
 
+/**
+ * Initialize the compression context.
+ */
+void LDM_initializeCCtx(LDM_CCtx *cctx,
+                        const void *src, size_t srcSize,
+                        void *dst, size_t maxDstSize);
+/**
+ * Outputs compression statistics to stdout.
+ */
+void LDM_printCompressStats(const LDM_compressStats *stats,
+                            const LDM_hashEntry *hashTable,
+                            U32 hashTableSize);
+/**
+ * Checks whether the LDM_MIN_MATCH_LENGTH bytes from p are the same as the
+ * LDM_MIN_MATCH_LENGTH bytes from match.
+ *
+ * This assumes LDM_MIN_MATCH_LENGTH is a multiple of four.
+ *
+ * Return 1 if valid, 0 otherwise.
+ */
+int LDM_isValidMatch(const BYTE *pIn, const BYTE *pMatch);
+
+/**
+ *  Counts the number of bytes that match from pIn and pMatch,
+ *  up to pInLimit.
+ */
+U32 LDM_countMatchLength(const BYTE *pIn, const BYTE *pMatch,
+                         const BYTE *pInLimit);
+
+/**
+ * Encode the literal length followed by the literals.
+ *
+ * The literal length is written to the upper four bits of pToken, with
+ * additional bytes written to the output as needed (see lz4).
+ *
+ * This is followed by literalLength bytes corresponding to the literals.
+ */
+void LDM_encodeLiteralLengthAndLiterals(
+    LDM_CCtx *cctx, BYTE *pToken, const U32 literalLength);
+
+/**
+ * Write current block (literals, literal length, match offset,
+ * match length).
+ */
+void LDM_outputBlock(LDM_CCtx *cctx,
+                     const U32 literalLength,
+                     const U32 offset,
+                     const U32 matchLength);
+
+/**
+ * Decompresses src into dst.
+ *
+ * Note: assumes src does not have a header.
+ */
 size_t LDM_decompress(const void *src, size_t srcSize,
                       void *dst, size_t maxDstSize);
 
+/**
+ * Initialize the decompression context.
+ */
+void LDM_initializeDCtx(LDM_DCtx *dctx,
+                        const void *src, size_t compressedSize,
+                        void *dst, size_t maxDecompressedSize);
+
 /**
  * Reads the header from src and writes the compressed size and
- * decompressed size into compressSize and decompressSize respectively.
+ * decompressed size into compressedSize and decompressedSize respectively.
  *
  * NB: LDM_compress and LDM_decompress currently do not add/read headers.
  */
-void LDM_readHeader(const void *src, U64 *compressSize,
-                    U64 *decompressSize);
+void LDM_readHeader(const void *src, U64 *compressedSize,
+                    U64 *decompressedSize);
 
 void LDM_test(void);