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76 lines
2.3 KiB
C++
76 lines
2.3 KiB
C++
#ifndef TOOLBOX_SELECT_H
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#define TOOLBOX_SELECT_H
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#include "tools/tools.h"
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#include <sys/types.h>
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/* cTBSelect provides an interface for polling UNIX-like file descriptors. */
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class cTBSelect {
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private:
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int m_MaxFiled;
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fd_set m_FdsQuery[2];
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fd_set m_FdsResult[2];
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public:
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cTBSelect(void);
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virtual ~cTBSelect();
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/* Clear() resets the object for use in a new Select() call. All file
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descriptors and their previous states are invalidated. */
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virtual void Clear(void);
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/* Add() adds a file descriptor to be polled in the next Select() call.
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That call polls if the file is readable if Output is set to false,
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writeable otherwise. */
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virtual bool Add(int Filed, bool Output = false);
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/* Select() polls all descriptors added by Add() and returns as soon as
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one of those changes state (gets readable/writeable), or after
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TimeoutMs milliseconds, whichever happens first. It returns the number
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of filedescriptors that have changed state. On error, -1 is returned
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and errno is set appropriately. */
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virtual int Select(uint TimeoutMs);
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/* Select() polls all descriptors added by Add() and returns as soon as
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one of those changes state (gets readable/writeable). It returns the
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number of filedescriptors that have changed state. On error, -1 is
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returned and errno is set appropriately. */
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virtual int Select(void);
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/* CanRead() returns true if the descriptor has changed to readable during
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the last Select() call. Otherwise false is returned. */
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virtual bool CanRead(int FileNo) const;
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/* CanWrite() returns true if the descriptor has changed to writeable
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during the last Select() call. Otherwise false is returned. */
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virtual bool CanWrite(int FileNo) const;
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};
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inline void cTBSelect::Clear(void) {
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FD_ZERO(&m_FdsQuery[0]);
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FD_ZERO(&m_FdsQuery[1]);
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m_MaxFiled = -1;
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}
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inline bool cTBSelect::Add(int Filed, bool Output /* = false */) {
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if (Filed < 0) return false;
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FD_SET(Filed, &m_FdsQuery[Output ? 1 : 0]);
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if (Filed > m_MaxFiled) m_MaxFiled = Filed;
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return true;
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}
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inline bool cTBSelect::CanRead(int FileNo) const {
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if (FileNo < 0) return false;
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return FD_ISSET(FileNo, &m_FdsResult[0]);
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}
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inline bool cTBSelect::CanWrite(int FileNo) const {
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if (FileNo < 0) return false;
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return FD_ISSET(FileNo, &m_FdsResult[1]);
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}
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#endif // TOOLBOX_SELECT_H
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