【发布时间】：2016-12-30 15:48:28
【问题描述】：
我正在尝试通过套接字发送一些 zlib 压缩数据，然后在从套接字接收后将其膨胀到另一个代码中。我能够成功解压缩第一个数据包，但是后续数据包没有被解压缩，inflate 函数返回 -2 错误代码。以下是sn-ps的代码：
服务器.cpp
` //Main里面
{
z_stream defstream;
memset(&defstream, 0, sizeof(defstream));
defstream.zalloc = Z_NULL;
defstream.zfree = Z_NULL;
defstream.opaque = Z_NULL;
err = deflateInit(&defstream, Z_BEST_COMPRESSION);
if(err == Z_OK)
{
//do nothing
}
else
{
deflateEnd(&defstream);
exit(1);
}
std::string outstring;
int ret = 0;
char a[6] = "Hello" ;
while(1)
{
printf("Uncompressed size is: %lu\n", strlen(a));
printf("\n----------\n\n");
SendCompressString(a);
memset(a,'\0',6);
strncpy(a,"Hello",5);
}
return 0;}
int SendCompressString(char *a)
{
char xyx[100];
char abc[100];
int iLen = 0;
int iRetval = 0;
char b[100];
char c[100];
z_stream defstream;
defstream.zalloc = Z_NULL;
defstream.zfree = Z_NULL;
defstream.opaque = Z_NULL;
// setup "a" as the input and "b" as the compressed output
defstream.avail_in = (uInt)strlen(a)+1; // size of input, string + terminator
defstream.next_in = (Bytef *)a; // input char array
defstream.avail_out = (uInt)sizeof(b); // size of output
defstream.next_out = (Bytef *)b; // output char array
// the actual compression work.
deflateInit(&defstream, Z_BEST_COMPRESSION);
deflate(&defstream, Z_FINISH);
deflateEnd(&defstream);
printf("Compressed size is: %lu\n", strlen(b));
printf("Compressed string is: %s\n", b);
strncpy(xyx,"M1234",5);
sprintf(abc,"%04d",defstream.total_out);
strcat(xyx,abc);
memcpy(xyx + 9,b,defstream.total_out);
printf("Compressed string is: [%s\n]", xyx);
printf("\n----------\n\n");
iLen = defstream.total_out + 9;
if ((iRetval = Send(connected, (CHAR *)xyx,&iLen , 0)) == FALSE)
{
logError("ERROR IN SENDING THE DATA TO SOCKET");
logDebug3("Send Failed For IP Addr") ;
} return 0;}
客户端.cpp
z_stream infstream;
int err = 0;
infstream.next_in = Z_NULL;
infstream.avail_in = 0;
infstream.zalloc = Z_NULL;
infstream.zfree = Z_NULL;
infstream.opaque = Z_NULL;
err = inflateInit (&infstream);
if(err == Z_OK)
{
//do nothing
}
else
{
inflateEnd(&infstream);
exit(1);
}
struct timeval stop, start,start1;
while(1)
{
PcktCount++;
LogTaBLib.debug("%s|%s|%d|================== Waiting on socket %d ==============",basename(__FILE__),__func__,__LINE__, iMasterSoc);
memset(AppMsg, '\0', MAX_PACKET_SIZE);
pHeader = NULL;
Datas = NULL;
iLen1 = 9;
if ((iRetval = Recv(iMasterSoc,(CHAR *) AppMsg,&iLen1,MSG_PEEK)) == FALSE)
{
LogTaBLib.debug("%s|%s|%d|Dropped Exchange Response Receiving from Socket",basename(__FILE__),__func__,__LINE__);
LogTaBLib.info("%s|%s|%d| CONNECTION DOWN ",basename(__FILE__),__func__,__LINE__);
//break;
exit(1);
}
pHeader = (struct BCAST_HEADER_DATA *)AppMsg;
//TWIDDLE1(pHeader->dSeqNum);
//TWIDDLE1(pHeader->dMsgLen);
iLen1 = atoi((const char*)(AppMsg + 5)) + 9;
if (iLen1 < 1024)
{
memset(AppMsg, '\0', MAX_PACKET_SIZE);
if ((iRetval = Recv(iMasterSoc, (CHAR *)AppMsg,&iLen1,0)) == FALSE)
{
perror("The Error Is :");
LogTaBLib.debug("%s|%s|%d|Dropped Exchange Response Receiving from Socket",basename(__FILE__),__func__,__LINE__);
LogTaBLib.info("%s|%s|%d| CONNECTION DOWN ",basename(__FILE__),__func__,__LINE__);
//break;
exit(1);
}
}
else
{
CHAR *Ptr = NULL;
Ptr = (CHAR *) malloc (iLen1);
memset(Ptr,'\0',iLen1);
if ((iRetval = Recv(iMasterSoc, (CHAR *)Ptr,&iLen1,0)) == FALSE)
{
perror("The Error Is :");
LogTaBLib.debug("%s|%s|%d|Dropped Exchange Response Receiving from Socket",basename(__FILE__),__func__,__LINE__);
LogTaBLib.info("%s|%s|%d| CONNECTION DOWN ",basename(__FILE__),__func__,__LINE__);
exit(1);
}
free(Ptr);
Ptr = NULL;
continue;
}
pHeader = NULL;
pHeader = (struct BCAST_HEADER_DATA *)AppMsg;
//TWIDDLE1(pHeader->dSeqNum);
//TWIDDLE1(pHeader->dMsgLen);
iLen1 = iLen1 - 9;
if(CompressionFlag == TRUE)
{
memset(Uncompressed,'\0',MAX_PACKET_SIZE);
memset(CompData,'\0',MAX_PACKET_SIZE);
memcpy(CompData,AppMsg+9,iLen1);
LogTaBLib.info("%s|%s|%d| CompData Is [%s] iLen1 [%d]",basename(__FILE__),__func__,__LINE__,CompData,iLen1);
gettimeofday(&start, NULL);
infstream.avail_in = iLen1 ;
infstream.next_in = (Bytef *)CompData; // input char array
infstream.avail_out = (uInt)sizeof(Uncompressed); // size of output
infstream.next_out = (Bytef *)Uncompressed; // output char array
err = inflate(&infstream, Z_NO_FLUSH);
if(err == Z_OK)
{
// do nothing
}
else
{
LogTaBLib.info("%s|%s|%d|Failed With [%d] ",basename(__FILE__),__func__,__LINE__,err);
inflateEnd(&infstream);
}
gettimeofday(&stop, NULL);
LogTaBLib.info("%s|%s|%d|Uncompressed[%s] Length[%d]",basename(__FILE__),__func__,__LINE__,Uncompressed,iLen1);
}
iLen1 =0;
memset(buffer,'\0',200);
`
这是发送的第一个字符串的输出：
INFO|2016-12-30|21:33:37,875443||||||TestZlib.cpp|main|481|未压缩[Hello] 长度[14]| 解码消息的秒数是：[54]
对于第二个和后续字符串，我得到与输入相同的字符串，但我无法解压缩：
INFO|2016-12-30|21:33:37,875739||||||TestZlib.cpp|main|481|Uncompressed[] 长度[14]|
【问题讨论】：
标签： c zlib compression