http: Add support for zstd compression

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/nxt_zstd.c b/src/nxt_zstd.c
new file mode 100644
index 00000000..8fb37944
--- /dev/null
+++ b/src/nxt_zstd.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (C) Andrew Clayton
+ * Copyright (C) F5, Inc.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <zstd.h>
+
+#include "nxt_http_compression.h"
+
+
+static int
+nxt_zstd_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    ZSTD_CStream  **zstd = &ctx->zstd_ctx;
+
+    *zstd = ZSTD_createCStream();
+    if (*zstd == NULL) {
+        return -1;
+    }
+    ZSTD_initCStream(*zstd, ctx->level);
+
+    return 0;
+}
+
+
+static size_t
+nxt_zstd_bound(const nxt_http_comp_compressor_ctx_t *ctx, size_t in_len)
+{
+    return ZSTD_compressBound(in_len);
+}
+
+
+static ssize_t
+nxt_zstd_compress(nxt_http_comp_compressor_ctx_t *ctx, const uint8_t *in_buf,
+                  size_t in_len, uint8_t *out_buf, size_t out_len, bool last)
+{
+    size_t          ret;
+    ZSTD_CStream    *zstd = ctx->zstd_ctx;
+    ZSTD_inBuffer   zinb = { .src = in_buf, .size = in_len };
+    ZSTD_outBuffer  zoutb = { .dst = out_buf, .size = out_len };
+
+    ret = ZSTD_compressStream(zstd, &zoutb, &zinb);
+
+    if (zinb.pos < zinb.size) {
+        ret = ZSTD_flushStream(zstd, &zoutb);
+    }
+
+    if (last) {
+        ret = ZSTD_endStream(zstd, &zoutb);
+        ZSTD_freeCStream(zstd);
+    }
+
+    if (ZSTD_isError(ret)) {
+        return -1;
+    }
+
+    return zoutb.pos;
+}
+
+
+const nxt_http_comp_operations_t  nxt_http_comp_zstd_ops = {
+    .init               = nxt_zstd_init,
+    .bound              = nxt_zstd_bound,
+    .deflate            = nxt_zstd_compress,
+};