http: Add zlib compression support

This adds support for both deflate & gzip compressors.

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

1 files changed, 89 insertions, 0 deletions

diff --git a/src/nxt_zlib.c b/src/nxt_zlib.c
new file mode 100644
index 00000000..191d32ec
--- /dev/null
+++ b/src/nxt_zlib.c
@@ -0,0 +1,89 @@
+/*
+ *
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <zlib.h>
+
+#include "nxt_http_compression.h"
+
+
+static void
+nxt_zlib_gzip_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    int       ret;
+    z_stream  *z = &ctx->zlib_ctx;
+
+    *z = (z_stream){};
+
+    ret = deflateInit2(z, ctx->level, Z_DEFLATED, 9 + 16, 8,
+                       Z_DEFAULT_STRATEGY);
+}
+
+
+static void
+nxt_zlib_deflate_init(nxt_http_comp_compressor_ctx_t *ctx)
+{
+    int       ret;
+    z_stream  *z = &ctx->zlib_ctx;
+
+    *z = (z_stream){};
+
+    ret = deflateInit2(z, ctx->level, Z_DEFLATED, 9, 8, Z_DEFAULT_STRATEGY);
+}
+
+
+static size_t
+nxt_zlib_bound(const nxt_http_comp_compressor_ctx_t *ctx, size_t in_len)
+{
+    z_stream  *z = (z_stream *)&ctx->zlib_ctx;
+
+    return deflateBound(z, in_len);
+}
+
+
+static ssize_t
+nxt_zlib_deflate(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)
+{
+    int       ret;
+    size_t    compressed_bytes;
+    z_stream  *z = &ctx->zlib_ctx;
+
+    z->avail_in = in_len;
+    z->next_in = (z_const Bytef *)in_buf;
+
+    z->avail_out = out_len;
+    z->next_out = out_buf;
+
+    compressed_bytes = z->total_out;
+
+    ret = deflate(z, last ? Z_FINISH : Z_SYNC_FLUSH);
+    if (ret == Z_STREAM_ERROR || ret == Z_BUF_ERROR) {
+        deflateEnd(z);
+        printf("%s: ret = %d\n", __func__, ret);
+        return -1;
+    }
+
+    if (last)
+        deflateEnd(z);
+
+    return z->total_out - compressed_bytes;
+}
+
+
+const nxt_http_comp_operations_t  nxt_comp_deflate_ops = {
+    .init               = nxt_zlib_deflate_init,
+    .bound              = nxt_zlib_bound,
+    .deflate            = nxt_zlib_deflate,
+};
+
+
+const nxt_http_comp_operations_t  nxt_comp_gzip_ops = {
+    .init               = nxt_zlib_gzip_init,
+    .bound              = nxt_zlib_bound,
+    .deflate            = nxt_zlib_deflate,
+};