homework-jianmu/source/util/src/tencode.c

138 lines
3.3 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _DEFAULT_SOURCE
#include "tencode.h"
#if __STDC_VERSION__ >= 201112L
static_assert(sizeof(float) == sizeof(uint32_t), "sizeof(float) must equal to sizeof(uint32_t)");
static_assert(sizeof(double) == sizeof(uint64_t), "sizeof(double) must equal to sizeof(uint64_t)");
#endif
void tCoderInit(SCoder* pCoder, td_endian_t endian, uint8_t* data, int32_t size, td_coder_t type) {
if (type == TD_ENCODER) {
if (data == NULL) size = 0;
} else {
ASSERT(data && size > 0);
}
pCoder->type = type;
pCoder->endian = endian;
pCoder->data = data;
pCoder->size = size;
pCoder->pos = 0;
tFreeListInit(&(pCoder->fl));
TD_SLIST_INIT(&(pCoder->stack));
}
void tCoderClear(SCoder* pCoder) {
tFreeListClear(&(pCoder->fl));
struct SCoderNode* pNode;
for (;;) {
pNode = TD_SLIST_HEAD(&(pCoder->stack));
if (pNode == NULL) break;
TD_SLIST_POP(&(pCoder->stack));
free(pNode);
}
}
int32_t tStartEncode(SCoder* pCoder) {
struct SCoderNode* pNode;
ASSERT(pCoder->type == TD_ENCODER);
if (pCoder->data) {
if (pCoder->size - pCoder->pos < sizeof(int32_t)) return -1;
pNode = malloc(sizeof(*pNode));
if (pNode == NULL) return -1;
pNode->data = pCoder->data;
pNode->pos = pCoder->pos;
pNode->size = pCoder->size;
pCoder->data = pNode->data + pNode->pos + sizeof(int32_t);
pCoder->pos = 0;
pCoder->size = pNode->size - pNode->pos - sizeof(int32_t);
TD_SLIST_PUSH(&(pCoder->stack), pNode);
} else {
pCoder->pos += sizeof(int32_t);
}
return 0;
}
void tEndEncode(SCoder* pCoder) {
struct SCoderNode* pNode;
int32_t len;
ASSERT(pCoder->type == TD_ENCODER);
if (pCoder->data) {
pNode = TD_SLIST_HEAD(&(pCoder->stack));
ASSERT(pNode);
TD_SLIST_POP(&(pCoder->stack));
len = pCoder->pos;
pCoder->data = pNode->data;
pCoder->size = pNode->size;
pCoder->pos = pNode->pos;
tEncodeI32(pCoder, len);
TD_CODER_MOVE_POS(pCoder, len);
free(pNode);
}
}
int32_t tStartDecode(SCoder* pCoder) {
int32_t len;
struct SCoderNode* pNode;
ASSERT(pCoder->type == TD_DECODER);
if (tDecodeI32(pCoder, &len) < 0) return -1;
pNode = malloc(sizeof(*pNode));
if (pNode == NULL) return -1;
pNode->data = pCoder->data;
pNode->pos = pCoder->pos;
pNode->size = pCoder->size;
pCoder->data = pNode->data + pNode->pos;
pCoder->size = len;
pCoder->pos = 0;
TD_SLIST_PUSH(&(pCoder->stack), pNode);
return 0;
}
void tEndDecode(SCoder* pCoder) {
struct SCoderNode* pNode;
ASSERT(pCoder->type == TD_DECODER);
pNode = TD_SLIST_HEAD(&(pCoder->stack));
ASSERT(pNode);
TD_SLIST_POP(&(pCoder->stack));
pCoder->data = pNode->data;
pCoder->pos = pCoder->size + pNode->pos;
pCoder->size = pNode->size;
free(pNode);
}