text: /*
   *
   * Copyright 2015 gRPC authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   */
  
  #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_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)(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_chttp2_hpack_parser* p);
  void grpc_chttp2_hpack_parser_destroy(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_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(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 */
  