http: Add zlib compression support

This adds support for both deflate & gzip compressors.

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

3 files changed, 129 insertions, 0 deletions

diff --git a/src/nxt_http_compression.c b/src/nxt_http_compression.c
index d2ee1332..0c2931a9 100644
--- a/src/nxt_http_compression.c
+++ b/src/nxt_http_compression.c
@@ -26,6 +26,10 @@ typedef struct nxt_http_comp_ctx_s         nxt_http_comp_ctx_t;
 
 enum nxt_http_comp_scheme_e {
     NXT_HTTP_COMP_SCHEME_IDENTITY = 0,
+#if NXT_HAVE_ZLIB
+    NXT_HTTP_COMP_SCHEME_DEFLATE,
+    NXT_HTTP_COMP_SCHEME_GZIP,
+#endif
 
     /* keep last */
     NXT_HTTP_COMP_SCHEME_UNKNOWN
@@ -85,6 +89,22 @@ static const nxt_http_comp_type_t  compressors[] = {
     {
         .token      = nxt_string("identity"),
         .scheme     = NXT_HTTP_COMP_SCHEME_IDENTITY,
+#if NXT_HAVE_ZLIB
+    }, {
+        .token      = nxt_string("deflate"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_DEFLATE,
+        .def_compr  = NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL,
+        .comp_min   = NXT_HTTP_COMP_ZLIB_COMP_MIN,
+        .comp_max   = NXT_HTTP_COMP_ZLIB_COMP_MAX,
+        .cops       = &nxt_comp_deflate_ops,
+    }, {
+        .token      = nxt_string("gzip"),
+        .scheme     = NXT_HTTP_COMP_SCHEME_GZIP,
+        .def_compr  = NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL,
+        .comp_min   = NXT_HTTP_COMP_ZLIB_COMP_MIN,
+        .comp_max   = NXT_HTTP_COMP_ZLIB_COMP_MAX,
+        .cops       = &nxt_comp_gzip_ops,
+#endif
     },
 };
 
diff --git a/src/nxt_http_compression.h b/src/nxt_http_compression.h
index 3d84cb1d..c67cd001 100644
--- a/src/nxt_http_compression.h
+++ b/src/nxt_http_compression.h
@@ -12,12 +12,23 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#if NXT_HAVE_ZLIB
+#include <zlib.h>
+#endif
+
 #include <nxt_main.h>
 #include <nxt_router.h>
 #include <nxt_string.h>
 #include <nxt_conf.h>
 
 
+#if NXT_HAVE_ZLIB
+#define NXT_HTTP_COMP_ZLIB_DEFAULT_LEVEL       Z_DEFAULT_COMPRESSION
+#define NXT_HTTP_COMP_ZLIB_COMP_MIN            Z_DEFAULT_COMPRESSION
+#define NXT_HTTP_COMP_ZLIB_COMP_MAX            Z_BEST_COMPRESSION
+#endif
+
+
 typedef struct nxt_http_comp_compressor_ctx_s  nxt_http_comp_compressor_ctx_t;
 typedef struct nxt_http_comp_operations_s      nxt_http_comp_operations_t;
 
@@ -25,6 +36,9 @@ struct nxt_http_comp_compressor_ctx_s {
     int8_t level;
 
     union {
+#if NXT_HAVE_ZLIB
+        z_stream zlib_ctx;
+#endif
     };
 };
 
@@ -39,6 +53,12 @@ struct nxt_http_comp_operations_s {
 };
 
 
+#if NXT_HAVE_ZLIB
+extern const nxt_http_comp_operations_t  nxt_comp_deflate_ops;
+extern const nxt_http_comp_operations_t  nxt_comp_gzip_ops;
+#endif
+
+
 extern bool nxt_http_comp_wants_compression(void);
 extern bool nxt_http_comp_compressor_is_valid(const nxt_str_t *token);
 extern nxt_int_t nxt_http_comp_check_compression(nxt_task_t *task,
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,
+};