1 files changed, 179 insertions, 0 deletions
diff --git a/src/nxt_http_compress_gzip.c b/src/nxt_http_compress_gzip.c
new file mode 100644
index 00000000..75ed9155
--- /dev/null
+++ b/src/nxt_http_compress_gzip.c
@@ -0,0 +1,179 @@
+/*
+ * Copyright (C) Alejandro Colomar
+ * Copyright (C) NGINX, Inc.
+ */
+
+
+#include "nxt_http_compress_gzip.h"
+
+#include <stddef.h>
+
+#include <zlib.h>
+
+#include <nxt_unit_cdefs.h>
+
+#include "nxt_buf.h"
+#include "nxt_clang.h"
+#include "nxt_errno.h"
+#include "nxt_http.h"
+#include "nxt_http_compress.h"
+#include "nxt_http_filter.h"
+#include "nxt_main.h"
+#include "nxt_mp.h"
+#include "nxt_router.h"
+#include "nxt_string.h"
+#include "nxt_types.h"
+
+
+typedef struct nxt_http_compress_gzip_ctx_s  nxt_http_compress_gzip_ctx_t;
+
+
+struct nxt_http_compress_gzip_ctx_s {
+    nxt_http_request_t  *r;
+    nxt_buf_t           *b;
+
+    z_stream            z;
+};
+
+
+static nxt_http_compress_gzip_ctx_t *nxt_http_compress_gzip_ctx(
+    nxt_task_t *task, nxt_http_request_t *r, nxt_http_compress_conf_t *conf);
+
+static void nxt_http_compress_gzip_filter(nxt_task_t *task, void *obj,
+    void *data);
+
+
+nxt_int_t
+nxt_http_compress_gzip(nxt_task_t *task, nxt_http_request_t *r,
+    nxt_http_compress_conf_t *conf)
+{
+    nxt_int_t                     ret;
+    nxt_http_compress_gzip_ctx_t  *ctx;
+
+    static nxt_str_t  ce = nxt_string("Content-Encoding");
+    static nxt_str_t  gzip = nxt_string("gzip");
+
+    if (r->body_handler == NULL
+        || r->resp.content_length_n == 0
+        || (r->resp.content_length != NULL
+            && r->resp.content_length->value_length == 1
+            && r->resp.content_length->value[0] == '0'))
+    {
+        return NXT_OK;
+    }
+
+    r->resp.content_length = NULL;
+    r->resp.content_length_n = -1;
+
+    ret = nxt_http_compress_append_field(task, r, &ce, &gzip);
+    if (nxt_slow_path(ret == NXT_ERROR)) {
+        return NXT_ERROR;
+    }
+
+    ctx = nxt_http_compress_gzip_ctx(task, r, conf);
+    if (nxt_slow_path(ctx == NULL)) {
+        return NXT_ERROR;
+    }
+
+    ret = nxt_http_filter_handler_add(r, nxt_http_compress_gzip_filter, ctx);
+    if (nxt_slow_path(ret == NXT_ERROR)) {
+        return NXT_ERROR;
+    }
+
+    return NXT_OK;
+}
+
+
+static nxt_http_compress_gzip_ctx_t *
+nxt_http_compress_gzip_ctx(nxt_task_t *task, nxt_http_request_t *r,
+    nxt_http_compress_conf_t *conf)
+{
+    int                           ret;
+    z_stream                      *z;
+    nxt_http_compress_gzip_ctx_t  *ctx;
+
+    ctx = nxt_mp_zget(r->mem_pool, sizeof(nxt_http_compress_gzip_ctx_t));
+    if (nxt_slow_path(ctx == NULL)) {
+        return NULL;
+    }
+
+    ctx->r = r;
+
+    z = &ctx->z;
+    z->zalloc = NULL;
+    z->zfree = NULL;
+    z->opaque = NULL;
+    ret = deflateInit2(z, Z_DEFAULT_COMPRESSION, Z_DEFLATED, MAX_WBITS + 16,
+                       MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+    if (nxt_slow_path(ret != 0)) {
+        return NULL;
+    }
+
+    return ctx;
+}
+
+
+static void
+nxt_http_compress_gzip_filter(nxt_task_t *task, void *obj, void *data)
+{
+    int                           ret;
+    ssize_t                       size;
+    z_stream                      *z;
+    nxt_buf_t                     **b, *tmp;
+    nxt_bool_t                    is_last;
+    nxt_http_request_t            *r;
+    nxt_http_compress_gzip_ctx_t  *ctx;
+
+    b = obj;
+    ctx = data;
+    z = &ctx->z;
+
+    r = ctx->r;
+
+    is_last = ((*b)->next != NULL
+               && (*b)->next->completion_handler != (*b)->completion_handler);
+
+    z->next_in = (*b)->mem.pos;
+    z->avail_in = (*b)->mem.free - (*b)->mem.pos;
+
+    size = deflateBound(z, z->avail_in);
+
+    tmp = nxt_buf_mem_alloc(r->mem_pool, size, 0);
+    if (nxt_slow_path(tmp == NULL)) {
+        return;
+    }
+
+    nxt_memcpy(tmp, *b, offsetof(nxt_buf_t, mem));
+    tmp->data = r->mem_pool;
+
+    z->next_out = tmp->mem.start;
+    z->avail_out = tmp->mem.end - tmp->mem.start;
+
+    ret = deflate(z, is_last ? Z_FINISH : Z_SYNC_FLUSH);
+    if (nxt_slow_path(ret == Z_STREAM_ERROR || ret == Z_BUF_ERROR)) {
+        goto fail;
+    }
+
+    tmp->mem.free = tmp->mem.end - z->avail_out;
+    size = tmp->mem.free - tmp->mem.start;
+
+    if ((*b)->mem.end - (*b)->mem.pos >= size) {
+        (*b)->mem.free = nxt_cpymem((*b)->mem.pos, tmp->mem.start, size);
+
+    } else {
+        nxt_swap(b, &tmp);
+    }
+
+fail:
+
+    nxt_mp_free(tmp->data, tmp);
+
+    if (is_last) {
+        ret = deflateEnd(z);
+        if (ret != Z_OK) {
+            return;
+        }
+    }
+
+    return;
+}