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在另一个代码中对其进行充气。我能够成功地压缩第一个数据包，但是后续数据包没有得到解压缩，返回-2错误代码的inflate函数。以下是代码段：
Server.cpp
`//在主要内部
{
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;}
Client.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] | 解码的秒数消息是：[54]
对于Second和Subsequent字符串，我得到与输入相同的字符串，但我无法解压缩它：
INFO | 2016-12-30 | 21：33：37,875739 |||||| TestZlib.cpp | main | 481 |未压缩[]长度[14] |
答案 0 :(得分：1)
-2是Z_STREAM_ERROR，这表示您在执行inflateInit()和inflate()之间的某个时候以某种方式破坏了zlib流数据结构。您应该检查所有memset()和memcpy()以确保它们保持在应该写入的内存范围内。
您还应该阅读documentation for zlib in zlib.h，并查看应使用inflate()和deflate()函数的example of how。例如，完全通胀的成功不是由Z_OK表示，而是由Z_STREAM_END表示。另外，您不会检查deflate*函数上的错误代码。
最后，您应该在单个程序中测试并验证deflate()和inflate()的使用情况，而不需要套接字，以确保在开始复杂化之前就已经完成了的东西。