Reuse zstd compression contexts, for a tiny speed boost.

[plocate] / plocate-build.cpp

diff --git a/plocate-build.cpp b/plocate-build.cpp
index a077ac1944358ecee7e622e9846982d7ba39c064..ed252fc5a5ac755efb23b6d1ea621d3d28e3cd37 100644 (file)
--- a/plocate-build.cpp
+++ b/plocate-build.cpp
@@ -4,8 +4,8 @@
 #include <algorithm>
 #include <assert.h>
 #include <chrono>
-#include <iosfwd>
 #include <getopt.h>
+#include <iosfwd>
 #include <math.h>
 #include <memory>
 #include <stdint.h>
@@ -300,7 +300,8 @@ string zstd_compress(const string &src, string *tempbuf)
        if (tempbuf->size() < max_size) {
                tempbuf->resize(max_size);
        }
-       size_t size = ZSTD_compress(&(*tempbuf)[0], max_size, src.data(), src.size(), /*level=*/6);
+       static ZSTD_CCtx *ctx = ZSTD_createCCtx();  // Reused across calls.
+       size_t size = ZSTD_compressCCtx(ctx, &(*tempbuf)[0], max_size, src.data(), src.size(), /*level=*/6);
        return string(tempbuf->data(), size);
 }