buffer.h

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/*
 * buffer.h -- generic memory buffer.
 *
 * Copyright (c) 2005-2008, NLnet Labs. All rights reserved.
 *
 * See LICENSE for the license.
 *
 *
 * The buffer module implements a generic buffer.  The API is based on
 * the java.nio.Buffer interface.
 */
 
#ifndef LDNS_BUFFER_H
#define LDNS_BUFFER_H
 
#include <assert.h>
#include <stdarg.h>
#include <string.h>
 
#include <ldns/error.h>
#include <ldns/common.h>
 
#include "ldns/util.h"
 
#ifdef __cplusplus
extern "C" {
#endif
 
#define LDNS_MIN_BUFLEN 512
 
struct ldns_struct_buffer
{
        size_t   _position;
 
        size_t   _limit;
 
        size_t   _capacity;
 
        uint8_t *_data;
 
        unsigned _fixed : 1;
 
        ldns_status _status;
};
typedef struct ldns_struct_buffer ldns_buffer;
 
 
#ifdef NDEBUG
INLINE void
ldns_buffer_invariant(const ldns_buffer *ATTR_UNUSED(buffer))
{
}
#else
INLINE void
ldns_buffer_invariant(const ldns_buffer *buffer)
{
        assert(buffer != NULL);
        assert(buffer->_position <= buffer->_limit);
        assert(buffer->_limit <= buffer->_capacity);
        assert(buffer->_data != NULL);
}
#endif
 
ldns_buffer *ldns_buffer_new(size_t capacity);
 
void ldns_buffer_new_frm_data(ldns_buffer *buffer, const void *data, size_t size);
 
INLINE void ldns_buffer_clear(ldns_buffer *buffer)
{
        ldns_buffer_invariant(buffer);
 
        /* reset status here? */
 
        buffer->_position = 0;
        buffer->_limit = buffer->_capacity;
}
 
INLINE void ldns_buffer_flip(ldns_buffer *buffer)
{
        ldns_buffer_invariant(buffer);
 
        buffer->_limit = buffer->_position;
        buffer->_position = 0;
}
 
INLINE void ldns_buffer_rewind(ldns_buffer *buffer)
{
        ldns_buffer_invariant(buffer);
 
        buffer->_position = 0;
}
 
INLINE size_t
ldns_buffer_position(const ldns_buffer *buffer)
{
        return buffer->_position;
}
 
INLINE void
ldns_buffer_set_position(ldns_buffer *buffer, size_t mark)
{
        assert(mark <= buffer->_limit);
        buffer->_position = mark;
}
 
INLINE void
ldns_buffer_skip(ldns_buffer *buffer, ssize_t count)
{
        assert(buffer->_position + count <= buffer->_limit);
        buffer->_position += count;
}
 
INLINE size_t
ldns_buffer_limit(const ldns_buffer *buffer)
{
        return buffer->_limit;
}
 
INLINE void
ldns_buffer_set_limit(ldns_buffer *buffer, size_t limit)
{
        assert(limit <= buffer->_capacity);
        buffer->_limit = limit;
        if (buffer->_position > buffer->_limit)
                buffer->_position = buffer->_limit;
}
 
INLINE size_t
ldns_buffer_capacity(const ldns_buffer *buffer)
{
        return buffer->_capacity;
}
 
bool ldns_buffer_set_capacity(ldns_buffer *buffer, size_t capacity);
 
bool ldns_buffer_reserve(ldns_buffer *buffer, size_t amount);
 
INLINE uint8_t *
ldns_buffer_at(const ldns_buffer *buffer, size_t at)
{
        assert(at <= buffer->_limit);
        return buffer->_data + at;
}
 
INLINE uint8_t *
ldns_buffer_begin(const ldns_buffer *buffer)
{
        return ldns_buffer_at(buffer, 0);
}
 
INLINE uint8_t *
ldns_buffer_end(const ldns_buffer *buffer)
{
        return ldns_buffer_at(buffer, buffer->_limit);
}
 
INLINE uint8_t *
ldns_buffer_current(const ldns_buffer *buffer)
{
        return ldns_buffer_at(buffer, buffer->_position);
}
 
INLINE size_t
ldns_buffer_remaining_at(const ldns_buffer *buffer, size_t at)
{
        ldns_buffer_invariant(buffer);
        assert(at <= buffer->_limit);
        return buffer->_limit - at;
}
 
INLINE size_t
ldns_buffer_remaining(const ldns_buffer *buffer)
{
        return ldns_buffer_remaining_at(buffer, buffer->_position);
}
 
INLINE int
ldns_buffer_available_at(const ldns_buffer *buffer, size_t at, size_t count)
{
        return count <= ldns_buffer_remaining_at(buffer, at);
}
 
INLINE int
ldns_buffer_available(const ldns_buffer *buffer, size_t count)
{
        return ldns_buffer_available_at(buffer, buffer->_position, count);
}
 
INLINE void
ldns_buffer_write_at(ldns_buffer *buffer, size_t at, const void *data, size_t count)
{
        assert(ldns_buffer_available_at(buffer, at, count));
        memcpy(buffer->_data + at, data, count);
}
 
INLINE void
ldns_buffer_write(ldns_buffer *buffer, const void *data, size_t count)
{
        ldns_buffer_write_at(buffer, buffer->_position, data, count);
        buffer->_position += count;
}
 
INLINE void
ldns_buffer_write_string_at(ldns_buffer *buffer, size_t at, const char *str)
{
        ldns_buffer_write_at(buffer, at, str, strlen(str));
}
 
INLINE void
ldns_buffer_write_string(ldns_buffer *buffer, const char *str)
{
        ldns_buffer_write(buffer, str, strlen(str));
}
 
INLINE void
ldns_buffer_write_chars(ldns_buffer *buffer, const char *str)
{
        if (!ldns_buffer_reserve(buffer, strlen(str)))
                buffer->_status = LDNS_STATUS_MEM_ERR;
        else
                ldns_buffer_write_string(buffer, str);
}
 
 
INLINE void
ldns_buffer_write_u8_at(ldns_buffer *buffer, size_t at, uint8_t data)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
        buffer->_data[at] = data;
}
 
INLINE void
ldns_buffer_write_u8(ldns_buffer *buffer, uint8_t data)
{
        ldns_buffer_write_u8_at(buffer, buffer->_position, data);
        buffer->_position += sizeof(data);
}
 
INLINE void
ldns_buffer_write_char(ldns_buffer *buffer, uint8_t data)
{
        if (!ldns_buffer_reserve(buffer, sizeof(data)))
                buffer->_status = LDNS_STATUS_MEM_ERR;
        else
                ldns_buffer_write_u8(buffer, data);
}
 
INLINE void
ldns_buffer_write_u16_at(ldns_buffer *buffer, size_t at, uint16_t data)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
        ldns_write_uint16(buffer->_data + at, data);
}
 
INLINE void
ldns_buffer_write_u16(ldns_buffer *buffer, uint16_t data)
{
        ldns_buffer_write_u16_at(buffer, buffer->_position, data);
        buffer->_position += sizeof(data);
}
 
INLINE void
ldns_buffer_write_u32_at(ldns_buffer *buffer, size_t at, uint32_t data)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(data)));
        ldns_write_uint32(buffer->_data + at, data);
}
 
INLINE void
ldns_buffer_write_u32(ldns_buffer *buffer, uint32_t data)
{
        ldns_buffer_write_u32_at(buffer, buffer->_position, data);
        buffer->_position += sizeof(data);
}
 
INLINE void
ldns_buffer_read_at(const ldns_buffer *buffer, size_t at, void *data, size_t count)
{
        assert(ldns_buffer_available_at(buffer, at, count));
        memcpy(data, buffer->_data + at, count);
}
 
INLINE void
ldns_buffer_read(ldns_buffer *buffer, void *data, size_t count)
{
        ldns_buffer_read_at(buffer, buffer->_position, data, count);
        buffer->_position += count;
}
 
INLINE uint8_t
ldns_buffer_read_u8_at(const ldns_buffer *buffer, size_t at)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(uint8_t)));
        return buffer->_data[at];
}
 
INLINE uint8_t
ldns_buffer_read_u8(ldns_buffer *buffer)
{
        uint8_t result = ldns_buffer_read_u8_at(buffer, buffer->_position);
        buffer->_position += sizeof(uint8_t);
        return result;
}
 
INLINE uint16_t
ldns_buffer_read_u16_at(ldns_buffer *buffer, size_t at)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(uint16_t)));
        return ldns_read_uint16(buffer->_data + at);
}
 
INLINE uint16_t
ldns_buffer_read_u16(ldns_buffer *buffer)
{
        uint16_t result = ldns_buffer_read_u16_at(buffer, buffer->_position);
        buffer->_position += sizeof(uint16_t);
        return result;
}
 
INLINE uint32_t
ldns_buffer_read_u32_at(ldns_buffer *buffer, size_t at)
{
        assert(ldns_buffer_available_at(buffer, at, sizeof(uint32_t)));
        return ldns_read_uint32(buffer->_data + at);
}
 
INLINE uint32_t
ldns_buffer_read_u32(ldns_buffer *buffer)
{
        uint32_t result = ldns_buffer_read_u32_at(buffer, buffer->_position);
        buffer->_position += sizeof(uint32_t);
        return result;
}
 
INLINE ldns_status
ldns_buffer_status(const ldns_buffer *buffer)
{
        return buffer->_status;
}
 
INLINE bool
ldns_buffer_status_ok(const ldns_buffer *buffer)
{
        if (buffer) {
                return ldns_buffer_status(buffer) == LDNS_STATUS_OK;
        } else {
                return false;
        }
}
 
int ldns_buffer_printf(ldns_buffer *buffer, const char *format, ...);
/*      ATTR_FORMAT(printf, 2, 3);*/
 
void ldns_buffer_free(ldns_buffer *buffer);
 
void *ldns_buffer_export(ldns_buffer *buffer);
 
void ldns_buffer_copy(ldns_buffer* result, const ldns_buffer* from);
 
#ifdef __cplusplus
}
#endif
 
#endif /* LDNS_BUFFER_H */