sylar高性能服务器-日志(P69)内容记录

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p69:SocketStream封装

基于之前写的序列化模块封装了读和写，但是socket的API并不保证一定能够写或读到规定的字节数，所以封装了readFixSize、writeFixSize保证一定操作规定字节的数据。

class Stream

基本读写操作

// 读操作，保存到buffer中 virtual int read(void* buffer, size_t length) = 0; // 读操作，保存到ByteArray中 virtual int read(ByteArray::ptr ba, size_t length) = 0; // 写操作，从buffer中写 virtual int write(const void* buffer, size_t length) = 0; // 写操作，从ByteArray中写 virtual int write(ByteArray::ptr ba, size_t length) = 0; 

readFixSize

// 读固定长度的数据，读取到内存 int Stream::readFixSize(void* buffer, size_t length) { 
    // 偏移量 size_t offset = 0; // 读取长度 int64_t left = length; while(left > 0) { 
    // len表示已经读取的数据大小 int64_t len = read((char*)buffer + offset, left); // 异常 if(len <= 0) { 
    return len; } // 更新偏移量 offset += len; // 更新剩余读取长度 left -= len; } // 返回读取到内存中的数据长度 return length; } // 读固定长度的数据，读取到ByteArray 因为ByteArray对象内部有一个位置指针，所以不需要手动更新偏移量 int Stream::readFixSize(ByteArray::ptr ba, size_t length) { 
    int64_t left = length; while(left > 0) { 
    int64_t len = read(ba, left); if(len <= 0) { 
    return len; } left -= len; } return length; } 

writeFixSize

// 写固定长度的数据，从内存写 int Stream::writeFixSize(const void* buffer, size_t length) { 
    size_t offset = 0; int64_t left = length; while(left > 0) { 
    int64_t len = write((const char*)buffer + offset, left); if(len <= 0) { 
    return len; } offset += len; left -= len; } return length; } // 写固定长度的数据，从ByteArray写 int Stream::writeFixSize(ByteArray::ptr ba, size_t length) { 
    int64_t left = length; while(left > 0) { 
    int64_t len = write(ba, left); if(len <= 0) { 
    return len; } left -= len; } return length; } 

class SocketStream

成员函数

/// Socket类 Socket::ptr m_socket; /// 是否主控 bool m_owner; 

read

// 读数据，读取到内存 int SocketStream::read(void* buffer, size_t length) { 
    if(!isConnected()) { 
    return -1; } return m_socket->recv(buffer, length); } // 读数据，读取到ByteArray int SocketStream::read(ByteArray::ptr ba, size_t length) { 
    if(!isConnected()) { 
    return -1; } std::vector<iovec> iovs; ba->getWriteBuffers(iovs, length); int rt = m_socket->recv(&iovs[0], iovs.size()); if(rt > 0) { 
    ba->setPosition(ba->getPosition() + rt); } return rt; } 

write

int SocketStream::write(const void* buffer, size_t length) { 
    if(!isConnected()) { 
    return -1; } return m_socket->send(buffer, length); } int SocketStream::write(ByteArray::ptr ba, size_t length) { 
    if(!isConnected()) { 
    return -1; } std::vector<iovec> iovs; ba->getReadBuffers(iovs, length); int rt = m_socket->send(&iovs[0], iovs.size()); if(rt > 0) { 
    ba->setPosition(ba->getPosition() + rt); } return rt; }