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/** @file
A brief file description
@section license License
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you 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 __ARENA_H__
#define __ARENA_H__
#include <sys/types.h>
#include <memory.h>
#include "ink_assert.h"
struct ArenaBlock
{
ArenaBlock *next;
char *m_heap_end;
char *m_water_level;
char data[8];
};
class Arena
{
public:
Arena():m_blocks(NULL)
{
}
~Arena()
{
reset();
}
inkcoreapi void *alloc(size_t size, size_t alignment = sizeof(double));
void free(void *mem, size_t size);
size_t str_length(const char *str);
char *str_alloc(size_t len);
void str_free(char *str);
char *str_store(const char *str, size_t len);
inkcoreapi void reset();
private:
ArenaBlock * m_blocks;
};
/*-------------------------------------------------------------------------
-------------------------------------------------------------------------*/
inline size_t
Arena::str_length(const char *str)
{
unsigned char *s, *e;
size_t len;
e = (unsigned char *) str;
s = e - 1;
while (*s >= 128) {
s -= 1;
}
len = *s++;
while (s != e) {
len = (len * 128) + (255 - *s++);
}
return len;
}
/*-------------------------------------------------------------------------
layout = [length][data]
length 1 = [1]
length 127 = [127]
length 128 = [1][255]
length 128 + 1 = [1][254]
length 128 + 2 = [1][253]
length 128 + 127 = [1][128]
length 128 + 128 = [2][255]
length 128 * 128 = [1][255][255]
length 128 * 128 + 1 = [1][255][254]
length 128 * 128 + 2 = [1][255][253]
length 128 * 128 + 127 = [1][255][128]
length 128 * 128 + 128 = [1][254][255]
-------------------------------------------------------------------------*/
inline char *
Arena::str_alloc(size_t len)
{
unsigned char *mem, *p;
size_t size;
size_t tmp;
size = len + 1 + 1;
tmp = len;
while (tmp >= 128) {
size += 1;
tmp /= 128;
}
mem = (unsigned char *) alloc(size, 1);
mem += (size - len - 1);
p = mem - 1;
tmp = len;
while (tmp >= 128) {
*p-- = (unsigned char) (255 - (tmp % 128));
tmp /= 128;
}
*p = (unsigned char) tmp;
return (char *) mem;
}
/*-------------------------------------------------------------------------
-------------------------------------------------------------------------*/
inline void
Arena::str_free(char *str)
{
unsigned char *p, *s, *e;
size_t len;
e = (unsigned char *) str;
s = e - 1;
while (*s >= 128) {
s -= 1;
}
p = s;
len = *s++;
while (s != e) {
len = (len * 128) + (255 - *s++);
}
len += (e - p) + 1;
free(p, len);
}
/*-------------------------------------------------------------------------
-------------------------------------------------------------------------*/
inline char *
Arena::str_store(const char *str, size_t len)
{
char *mem;
mem = str_alloc(len);
memcpy(mem, str, len);
mem[len] = '\0';
return mem;
}
#endif /* __ARENA_H__ */
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