nghttp2_hd: Adjust maximum size to index based on table size

lib/nghttp2_hd.c

@@ -926,8 +926,14 @@ nghttp2_hd_entry* nghttp2_hd_table_get(nghttp2_hd_context *context,
 #define name_match(NV, NAME)                                            \
   (nv->namelen == sizeof(NAME) - 1 && memeq(nv->name, NAME, sizeof(NAME) - 1))
 
-static int should_indexing(const nghttp2_nv *nv)
+static int hd_deflate_should_indexing(nghttp2_hd_context *deflater,
+                                      const nghttp2_nv *nv)
 {
+  size_t table_size = nghttp2_min(deflater->deflate_hd_table_bufsize_max,
+                                  deflater->hd_table_bufsize_max);
+  if(entry_room(nv->namelen, nv->valuelen) > table_size * 3 / 4) {
+    return 0;
+  }
 #ifdef NGHTTP2_XHD
   return !name_match(nv, NGHTTP2_XHD);
 #else /* !NGHTTP2_XHD */
@@ -1020,8 +1026,7 @@ static int deflate_nv(nghttp2_hd_context *deflater,
     if(res.index != -1) {
       index = res.index;
     }
-    if(should_indexing(nv) &&
-       entry_room(nv->namelen, nv->valuelen) <= NGHTTP2_HD_MAX_ENTRY_SIZE) {
+    if(hd_deflate_should_indexing(deflater, nv)) {
       nghttp2_hd_entry *new_ent;
       if(index >= (ssize_t)deflater->hd_table.len) {
         nghttp2_nv nv_indname;

lib/nghttp2_hd.h

@@ -32,7 +32,6 @@
 #include <nghttp2/nghttp2.h>
 
 #define NGHTTP2_HD_DEFAULT_MAX_BUFFER_SIZE (1 << 12)
-#define NGHTTP2_HD_MAX_ENTRY_SIZE 3072
 #define NGHTTP2_HD_ENTRY_OVERHEAD 32
 
 /* Default size of maximum table buffer size for encoder. Even if

tests/nghttp2_hd_test.c

@@ -331,10 +331,11 @@ void test_nghttp2_hd_deflate_deflate_buffer(void)
 
   blocklen = nghttp2_hd_deflate_hd(&deflater, &buf, &buflen, 0, &nv3, 1);
   CU_ASSERT(blocklen > 0);
-  /* Now header table should be empty */
-  CU_ASSERT(0 == deflater.hd_table.len);
-  CU_ASSERT(0 == deflater.deflate_hd_tablelen);
-  CU_ASSERT(0 == deflater.deflate_hd_table_bufsize);
+  /* Now header table should be unchanged, because we don't index
+     large header */
+  CU_ASSERT(4 == deflater.hd_table.len);
+  CU_ASSERT(4 == deflater.deflate_hd_tablelen);
+  CU_ASSERT(156 == deflater.deflate_hd_table_bufsize);
 
   nghttp2_hd_deflate_free(&deflater);
 
@@ -401,34 +402,6 @@ void test_nghttp2_hd_deflate_deflate_buffer(void)
 
   nva_out_reset(&out);
 
-  blocklen = nghttp2_hd_deflate_hd(&deflater, &buf, &buflen, 0, &nv3, 1);
-  CU_ASSERT(blocklen > 0);
-  /* Now header table should look like this:
-   *
-   *  0: a..a, a..a (-)
-   *  1: k1, v1 (-)
-   *  2: k1000, v100 (-)
-   *  3: k100, v100 (-)
-   *  4: k10, v10 (-)
-   *  5: k1, v1   (-)
-   *
-   *  name/value of all entries must be NULL.
-   */
-  CU_ASSERT(6 == deflater.hd_table.len);
-  CU_ASSERT(0 == deflater.deflate_hd_tablelen);
-  CU_ASSERT(0 == deflater.deflate_hd_table_bufsize);
-  for(i = 0; i < 6; ++i) {
-    ent = nghttp2_hd_table_get(&deflater, i);
-    CU_ASSERT(0 == (ent->flags & NGHTTP2_HD_FLAG_REFSET));
-  }
-
-  CU_ASSERT(blocklen == inflate_hd(&inflater, &out, buf, blocklen));
-
-  CU_ASSERT(1 == out.nvlen);
-  assert_nv_equal(&nv3, out.nva, 1);
-
-  nva_out_reset(&out);
-
   free(buf);
   nghttp2_hd_inflate_free(&inflater);
   nghttp2_hd_deflate_free(&deflater);