Line data    Source code

       1             : /*
       2             :  *
       3             :  * Copyright 2015, Google Inc.
       4             :  * All rights reserved.
       5             :  *
       6             :  * Redistribution and use in source and binary forms, with or without
       7             :  * modification, are permitted provided that the following conditions are
       8             :  * met:
       9             :  *
      10             :  *     * Redistributions of source code must retain the above copyright
      11             :  * notice, this list of conditions and the following disclaimer.
      12             :  *     * Redistributions in binary form must reproduce the above
      13             :  * copyright notice, this list of conditions and the following disclaimer
      14             :  * in the documentation and/or other materials provided with the
      15             :  * distribution.
      16             :  *     * Neither the name of Google Inc. nor the names of its
      17             :  * contributors may be used to endorse or promote products derived from
      18             :  * this software without specific prior written permission.
      19             :  *
      20             :  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      21             :  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      22             :  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      23             :  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      24             :  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      25             :  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      26             :  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      27             :  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      28             :  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      29             :  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      30             :  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
      31             :  *
      32             :  */
      33             : 
      34             : #include "src/core/transport/chttp2/varint.h"
      35             : 
      36       21075 : gpr_uint32 grpc_chttp2_hpack_varint_length(gpr_uint32 tail_value) {
      37       21075 :   if (tail_value < (1 << 7)) {
      38       19626 :     return 2;
      39        1449 :   } else if (tail_value < (1 << 14)) {
      40        1423 :     return 3;
      41          26 :   } else if (tail_value < (1 << 21)) {
      42          26 :     return 4;
      43           0 :   } else if (tail_value < (1 << 28)) {
      44           0 :     return 5;
      45             :   } else {
      46           0 :     return 6;
      47             :   }
      48             : }
      49             : 
      50       21075 : void grpc_chttp2_hpack_write_varint_tail(gpr_uint32 tail_value,
      51             :                                          gpr_uint8* target,
      52             :                                          gpr_uint32 tail_length) {
      53       21075 :   switch (tail_length) {
      54             :     case 5:
      55           0 :       target[4] = (gpr_uint8)((tail_value >> 28) | 0x80);
      56             :     case 4:
      57           0 :       target[3] = (gpr_uint8)((tail_value >> 21) | 0x80);
      58             :     case 3:
      59          26 :       target[2] = (gpr_uint8)((tail_value >> 14) | 0x80);
      60             :     case 2:
      61        1449 :       target[1] = (gpr_uint8)((tail_value >> 7) | 0x80);
      62             :     case 1:
      63       21075 :       target[0] = (gpr_uint8)((tail_value) | 0x80);
      64             :   }
      65       21075 :   target[tail_length - 1] &= 0x7f;
      66       21075 : }