From: Danielle Rozenblit <drozenblit@fb.com>
Date: Fri, 9 Sep 2022 19:34:25 +0000 (-0700)
Subject: add sequence bound function
X-Git-Tag: v1.5.4^2~160^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=aa829988215273f8c8b1423e1a924b326168e09f;p=thirdparty%2Fzstd.git

add sequence bound function
---

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index 59d441b2a..8a0c2f191 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -3003,6 +3003,10 @@ static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
     zc->seqCollector.seqIndex += seqStoreSeqSize;
 }
 
+size_t ZSTD_sequenceBound(size_t srcSize) {
+    return (srcSize / ZSTD_MINMATCH_MIN) + 1;
+}
+
 size_t ZSTD_generateSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
                               size_t outSeqsSize, const void* src, size_t srcSize)
 {
diff --git a/lib/zstd.h b/lib/zstd.h
index 112012d26..cf3dd7e27 100644
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -1396,6 +1396,15 @@ typedef enum {
   ZSTD_sf_explicitBlockDelimiters = 1    /* Representation of ZSTD_Sequence contains explicit block delimiters */
 } ZSTD_sequenceFormat_e;
 
+/*! ZSTD_sequenceBound() :
+ * `srcSize` : size of the input buffer
+ *  @return : upper-bound for the number of sequences that can be generated
+ *            from a buffer of srcSize bytes
+ *
+ *  note : returns number of sequences - to get bytes, multiply by sizeof(ZSTD_Sequence).
+ */
+ZSTDLIB_STATIC_API size_t ZSTD_sequenceBound(size_t srcSize);
+
 /*! ZSTD_generateSequences() :
  * Generate sequences using ZSTD_compress2(), given a source buffer.
  *