text: /*
   *
   * Copyright 2015, Google Inc.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   *
   *     * Redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above
   * copyright notice, this list of conditions and the following disclaimer
   * in the documentation and/or other materials provided with the
   * distribution.
   *     * Neither the name of Google Inc. nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #ifndef GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H
  #define GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H
  
  #include <stddef.h>
  
  #include <grpc/support/port_platform.h>
  #include "src/core/ext/transport/chttp2/transport/frame.h"
  #include "src/core/ext/transport/chttp2/transport/hpack_table.h"
  #include "src/core/lib/iomgr/exec_ctx.h"
  #include "src/core/lib/transport/metadata.h"
  
  typedef struct grpc_chttp2_hpack_parser grpc_chttp2_hpack_parser;
  
  typedef grpc_error *(*grpc_chttp2_hpack_parser_state)(
      grpc_exec_ctx *exec_ctx, grpc_chttp2_hpack_parser *p, const uint8_t *beg,
      const uint8_t *end);
  
  typedef struct {
    bool copied;
    struct {
      grpc_slice referenced;
      struct {
        char *str;
        uint32_t length;
        uint32_t capacity;
      } copied;
    } data;
  } grpc_chttp2_hpack_parser_string;
  
  struct grpc_chttp2_hpack_parser {
    /* user specified callback for each header output */
    void (*on_header)(grpc_exec_ctx *exec_ctx, void *user_data, grpc_mdelem md);
    void *on_header_user_data;
  
    grpc_error *last_error;
  
    /* current parse state - or a function that implements it */
    grpc_chttp2_hpack_parser_state state;
    /* future states dependent on the opening op code */
    const grpc_chttp2_hpack_parser_state *next_state;
    /* what to do after skipping prioritization data */
    grpc_chttp2_hpack_parser_state after_prioritization;
    /* the refcount of the slice that we're currently parsing */
    grpc_slice_refcount *current_slice_refcount;
    /* the value we're currently parsing */
    union {
      uint32_t *value;
      grpc_chttp2_hpack_parser_string *str;
    } parsing;
    /* string parameters for each chunk */
    grpc_chttp2_hpack_parser_string key;
    grpc_chttp2_hpack_parser_string value;
    /* parsed index */
    uint32_t index;
    /* length of source bytes for the currently parsing string */
    uint32_t strlen;
    /* number of source bytes read for the currently parsing string */
    uint32_t strgot;
    /* huffman decoding state */
    int16_t huff_state;
    /* is the string being decoded binary? */
    uint8_t binary;
    /* is the current string huffman encoded? */
    uint8_t huff;
    /* is a dynamic table update allowed? */
    uint8_t dynamic_table_update_allowed;
    /* set by higher layers, used by grpc_chttp2_header_parser_parse to signal
       it should append a metadata boundary at the end of frame */
    uint8_t is_boundary;
    uint8_t is_eof;
    uint32_t base64_buffer;
  
    /* hpack table */
    grpc_chttp2_hptbl table;
  };
  
  void grpc_chttp2_hpack_parser_init(grpc_exec_ctx *exec_ctx,
                                     grpc_chttp2_hpack_parser *p);
  void grpc_chttp2_hpack_parser_destroy(grpc_exec_ctx *exec_ctx,
                                        grpc_chttp2_hpack_parser *p);
  
  void grpc_chttp2_hpack_parser_set_has_priority(grpc_chttp2_hpack_parser *p);
  
  grpc_error *grpc_chttp2_hpack_parser_parse(grpc_exec_ctx *exec_ctx,
                                             grpc_chttp2_hpack_parser *p,
                                             grpc_slice slice);
  
  /* wraps grpc_chttp2_hpack_parser_parse to provide a frame level parser for
     the transport */
  grpc_error *grpc_chttp2_header_parser_parse(grpc_exec_ctx *exec_ctx,
                                              void *hpack_parser,
                                              grpc_chttp2_transport *t,
                                              grpc_chttp2_stream *s,
                                              grpc_slice slice, int is_last);
  
  #endif /* GRPC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_HPACK_PARSER_H */
  