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_LIB_GPR_STRING_H
  #define GRPC_CORE_LIB_GPR_STRING_H
  
  #include <grpc/support/port_platform.h>
  
  #include <grpc/impl/codegen/gpr_types.h>
  
  #include <stdbool.h>
  #include <stddef.h>
  
  /* String utility functions */
  
  /* Flags for gpr_dump function. */
  #define GPR_DUMP_HEX 0x00000001
  #define GPR_DUMP_ASCII 0x00000002
  
  /* Converts array buf, of length len, into a C string according to the flags.
     Result should be freed with gpr_free() */
  char* gpr_dump(const char* buf, size_t len, uint32_t flags);
  /* Converts array buf, of length len, into a C string according to the flags.
     The length of the returned buffer is stored in out_len.
     Result should be freed with gpr_free() */
  char* gpr_dump_return_len(const char* buf, size_t len, uint32_t flags,
                            size_t* out_len);
  
  /* Parses an array of bytes into an integer (base 10). Returns 1 on success,
     0 on failure. */
  int gpr_parse_bytes_to_uint32(const char* data, size_t length,
                                uint32_t* result);
  
  /* Minimum buffer size for calling ltoa */
  #define GPR_LTOA_MIN_BUFSIZE (3 * sizeof(long))
  
  /* Convert a long to a string in base 10; returns the length of the
     output string (or 0 on failure).
     output must be at least GPR_LTOA_MIN_BUFSIZE bytes long. */
  int gpr_ltoa(long value, char* output);
  
  /* Minimum buffer size for calling int64toa */
  #define GPR_INT64TOA_MIN_BUFSIZE (3 * sizeof(int64_t))
  
  /* Convert an int64 to a string in base 10; returns the length of the
  output string (or 0 on failure).
  output must be at least GPR_INT64TOA_MIN_BUFSIZE bytes long.
  NOTE: This function ensures sufficient bit width even on Win x64,
  where long is 32bit is size.*/
  int int64_ttoa(int64_t value, char* output);
  
  // Parses a non-negative number from a value string.  Returns -1 on error.
  int gpr_parse_nonnegative_int(const char* value);
  
  /* Reverse a run of bytes */
  void gpr_reverse_bytes(char* str, int len);
  
  /* Pad a string with flag characters. The given length specifies the minimum
     field width. The input string is never truncated. */
  char* gpr_leftpad(const char* str, char flag, size_t length);
  
  /* Join a set of strings, returning the resulting string.
     Total combined length (excluding null terminator) is returned in total_length
     if it is non-null. */
  char* gpr_strjoin(const char** strs, size_t nstrs, size_t* total_length);
  
  /* Join a set of strings using a separator, returning the resulting string.
     Total combined length (excluding null terminator) is returned in total_length
     if it is non-null. */
  char* gpr_strjoin_sep(const char** strs, size_t nstrs, const char* sep,
                        size_t* total_length);
  
  void gpr_string_split(const char* input, const char* sep, char*** strs,
                        size_t* nstrs);
  
  /* Returns an allocated string that represents tm according to RFC-3339, and,
     more specifically, follows:
     https://developers.google.com/protocol-buffers/docs/proto3#json
  
     Uses RFC 3339, where generated output will always be Z-normalized and uses
     0, 3, 6 or 9 fractional digits. */
  char* gpr_format_timespec(gpr_timespec);
  
  /** Case insensitive string comparison... return <0 if lower(a)<lower(b), ==0 if
      lower(a)==lower(b), >0 if lower(a)>lower(b) */
  int gpr_stricmp(const char* a, const char* b);
  int gpr_strincmp(const char* a, const char* b, size_t n);
  
  void* gpr_memrchr(const void* s, int c, size_t n);
  
  /* Try to parse given string into a boolean value.
     When parsed successfully, dst will have the value and returns true.
     Otherwise, it returns false. */
  bool gpr_parse_bool_value(const char* value, bool* dst);
  
  #endif /* GRPC_CORE_LIB_GPR_STRING_H */
  