string_buffer.h

// Copyright 2010 Google Inc. All Rights Reserved.
//
// 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.
//
// Author: jdtang@google.com (Jonathan Tang)
//
#ifndef GUMBO_STRING_BUFFER_H_
#define GUMBO_STRING_BUFFER_H_

#include <stdbool.h>
#include <stddef.h>
#include <string.h>

#include "gumbo.h"

#ifdef __cplusplus
extern "C" {
#endif

// A struct representing a mutable, growable string.  This consists of a
// heap-allocated buffer that may grow (by doubling) as necessary.  When
// converting to a string, this allocates a new buffer that is only as long as
// it needs to be.  Note that the internal buffer here is *not* nul-terminated,
// so be sure not to use ordinary string manipulation functions on it.
typedef struct {
  // A pointer to the beginning of the string.  NULL iff length == 0.
  char* data;

  // The length of the string fragment, in bytes.  May be zero.
  size_t length;

  // The capacity of the buffer, in bytes.
  size_t capacity;
} GumboStringBuffer;

// Initializes a new GumboStringBuffer.
void gumbo_string_buffer_init(GumboStringBuffer* output);

// Ensures that the buffer contains at least a certain amount of space.  Most
// useful with snprintf and the other length-delimited string functions, which
// may want to write directly into the buffer.
void gumbo_string_buffer_reserve(size_t min_capacity, GumboStringBuffer* output);

// Appends a single Unicode codepoint onto the end of the GumboStringBuffer.
// This is essentially a UTF-8 encoder, and may add 1-4 bytes depending on the
// value of the codepoint.
void gumbo_string_buffer_append_codepoint(int c, GumboStringBuffer* output);

// Appends a string onto the end of the GumboStringBuffer.
void gumbo_string_buffer_append_string(GumboStringPiece* str, GumboStringBuffer* output);

// Converts this string buffer to const char*, alloctaing a new buffer for it.
char* gumbo_string_buffer_to_string(GumboStringBuffer* input);

// Reinitialize this string buffer.  This clears it by setting length=0.  It
// does not zero out the buffer itself.
void gumbo_string_buffer_clear(GumboStringBuffer* input);

// Deallocates this GumboStringBuffer.
void gumbo_string_buffer_destroy(GumboStringBuffer* buffer);

const char* gumbo_string_buffer_cstr(GumboStringBuffer *buffer);
void gumbo_string_buffer_put(GumboStringBuffer *buffer,
    const char *data, size_t length);

static inline void gumbo_string_buffer_puts(GumboStringBuffer *buffer,
    const char *data)
{
	gumbo_string_buffer_put(buffer, data, strlen(data));
}

void gumbo_string_buffer_putv(GumboStringBuffer *out, int n, ...);

#ifdef __cplusplus
}
#endif

#endif  // GUMBO_STRING_BUFFER_H_