w32sock.cpp

用于嵌入式环境的数据库

// Local windows sockets
//

int local_win_socket::read(void* buf, size_t min_size, size_t max_size, 
                           time_t timeout)
{
    time_t start = 0;
    char* dst = (char*)buf;
    size_t size = 0;
    Error = ok;
    if (timeout != WAIT_FOREVER) { 
        start = time(NULL); 
        timeout *= 1000; // convert seconds to miliseconds
    }
    while (size < min_size && state == ss_open) {       
        RcvBuf->RcvWaitFlag = true;
        serialize();
        size_t begin = RcvBuf->DataBeg;
        size_t end = RcvBuf->DataEnd;
        size_t rcv_size = (begin <= end)
            ? end - begin : sizeof(RcvBuf->Data) - begin;
        if (rcv_size > 0) { 
            RcvBuf->RcvWaitFlag = false;
            if (rcv_size >= max_size) { 
                memcpy(dst, &RcvBuf->Data[begin], max_size);
                begin += max_size;
                size += max_size;
            } else { 
                memcpy(dst, &RcvBuf->Data[begin], rcv_size);
                begin += rcv_size;
                dst += rcv_size;
                size += rcv_size;
                max_size -= rcv_size;
            } 
            RcvBuf->DataBeg = (begin == sizeof(RcvBuf->Data)) ? 0 : begin;
            if (RcvBuf->SndWaitFlag) { 
                SetEvent(Signal[RTR]);
            }           
        } else {
            HANDLE h[2];
            h[0] = Signal[RD];
            h[1] = Mutex;
            int rc = WaitForMultipleObjects(2, h, false, timeout);
            RcvBuf->RcvWaitFlag = false;
            if (rc != WAIT_OBJECT_0) {
                if (rc == WAIT_OBJECT_0+1 || rc == WAIT_ABANDONED+1) { 
                    Error = broken_pipe;
                    ReleaseMutex(Mutex);
                } else if (rc == WAIT_TIMEOUT) { 
                    return size;
                } else { 
                    Error = GetLastError();
                }
                return -1;
            }
            if (timeout != WAIT_FOREVER) { 
                time_t now = time(NULL);
                timeout = timeout >= (now - start)*1000 
                    ? timeout - (now - start)*1000 : 0;  
            }
        }
    }                   
    return size < min_size ? -1 : (int)size;
}


bool local_win_socket::write(const void* buf, size_t size)
{
    char* src = (char*)buf;
    Error = ok;
    while (size > 0 && state == ss_open) {      
        SndBuf->SndWaitFlag = true;
        serialize();
        size_t begin = SndBuf->DataBeg;
        size_t end = SndBuf->DataEnd;
        size_t snd_size = (begin <= end) 
            ? sizeof(SndBuf->Data) - end - (begin == 0)
            : begin - end - 1;
        if (snd_size > 0) { 
            SndBuf->SndWaitFlag = false;
            if (snd_size >= size) { 
                memcpy(&SndBuf->Data[end], src, size);
                end += size;
                size = 0;
            } else { 
                memcpy(&SndBuf->Data[end], src, snd_size);
                end += snd_size;
                src += snd_size;
                size -= snd_size;
            } 
            SndBuf->DataEnd = (end == sizeof(SndBuf->Data)) ? 0 : end;
            if (SndBuf->RcvWaitFlag) { 
                SetEvent(Signal[TD]);
            }           
        } else {
            HANDLE h[2];
            h[0] = Signal[RTT];
            h[1] = Mutex;
            int rc = WaitForMultipleObjects(2, h, false, INFINITE);
            RcvBuf->SndWaitFlag = false;
            if (rc != WAIT_OBJECT_0) {
                if (rc == WAIT_OBJECT_0+1 || rc == WAIT_ABANDONED+1) { 
                    Error = broken_pipe;
                    ReleaseMutex(Mutex);
                } else { 
                    Error = GetLastError();
                }       
                return false;
            }
        }
    }                           
    return size == 0;
}

#define MAX_ADDRESS_LEN 64

local_win_socket::local_win_socket(const char* address)
{
    Name = new char[strlen(address)+1];
    strcpy(Name, address);
    Error = not_opened;
    Mutex = NULL;
}
 
bool local_win_socket::open(int)
{
    char buf[MAX_ADDRESS_LEN];  
    int  i;

    for (i = RD; i <= RTT; i++) {  
        sprintf(buf, "%s.%c", Name, i + '0');
        Signal[i] = CreateEvent(FASTDB_SECURITY_ATTRIBUTES, false, false, buf);
        if (GetLastError() == ERROR_ALREADY_EXISTS) { 
            WaitForSingleObject(Signal[i], 0);
        }
        if (!Signal[i]) {
            Error = GetLastError();
            while (--i >= 0) { 
                CloseHandle(Signal[i]);
            }
            return false;
        }       
    }
    sprintf(buf, "%s.shr", Name);
    BufHnd = CreateFileMapping(INVALID_HANDLE_VALUE, FASTDB_SECURITY_ATTRIBUTES, PAGE_READWRITE,
                               0, sizeof(socket_buf)*2, buf);
    if (!BufHnd) {
        Error = GetLastError();
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        return false;
    }
    RcvBuf = (socket_buf*)MapViewOfFile(BufHnd, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (!RcvBuf) {
        Error = GetLastError();
        CloseHandle(BufHnd);
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        return false;
    }   
    SndBuf = RcvBuf+1;
    RcvBuf->DataBeg = RcvBuf->DataEnd = 0;
    SndBuf->DataBeg = SndBuf->DataEnd = 0;       
    Error = ok;
    state = ss_open;
    return true;
}

local_win_socket::local_win_socket()
{
    int i;
    BufHnd = NULL;
    Mutex = NULL; 
    Name = NULL;

    for (i = RD; i <= RTT; i++) {  
        Signal[i] = CreateEvent(FASTDB_SECURITY_ATTRIBUTES, false, false, NULL);
        if (!Signal[i]) {
            Error = GetLastError();
            while (--i >= 0) { 
                CloseHandle(Signal[i]);
            }
            return;
        }       
    }
    // create anonymous shared memory section
    BufHnd = CreateFileMapping(INVALID_HANDLE_VALUE, FASTDB_SECURITY_ATTRIBUTES, PAGE_READWRITE,
                               0, sizeof(socket_buf)*2, NULL);
    if (!BufHnd) {
        Error = GetLastError();
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        return;
    }
    RcvBuf = (socket_buf*)MapViewOfFile(BufHnd, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (!RcvBuf) {
        Error = GetLastError();
        CloseHandle(BufHnd);
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        BufHnd = NULL;
        return;
    }   
    SndBuf = RcvBuf+1;
    RcvBuf->DataBeg = RcvBuf->DataEnd = 0;
    SndBuf->DataBeg = SndBuf->DataEnd = 0;       
    Error = ok;
    state = ss_open;
}

local_win_socket::~local_win_socket()
{
    close();
    delete[] Name;
}       

socket_t* local_win_socket::accept()
{   
    HANDLE h[2];

    if (state != ss_open) {     
        return NULL;
    }
                    
    connect_data* cdp = (connect_data*)SndBuf->Data;
    cdp->Pid = GetCurrentProcessId();
    cdp->Mutex = WatchDogMutex;
    while (true) { 
        SetEvent(Signal[RTR]);
        int rc = WaitForSingleObject(Signal[RD], ACCEPT_TIMEOUT);
        if (rc == WAIT_OBJECT_0) {
            if (state != ss_open) { 
                Error = not_opened;
                return NULL;
            }
            Error = ok;
            break;
        } else if (rc != WAIT_TIMEOUT) { 
            Error = GetLastError();
            return NULL;
        }
    }
    local_win_socket* sock = new local_win_socket();
    sock->Mutex = ((connect_data*)RcvBuf->Data)->Mutex;
    accept_data* adp = (accept_data*)SndBuf->Data;
    adp->BufHnd = sock->BufHnd;
    for (int i = RD; i <= RTT; i++) { 
        adp->Signal[(i + TD - RD) & RTT] = sock->Signal[i]; 
    }
    SetEvent(Signal[TD]);
    h[0] = Signal[RD];
    h[1] = sock->Mutex;
    int rc = WaitForMultipleObjects(2, h, false, INFINITE);
    if (rc != WAIT_OBJECT_0) {
        if (rc == WAIT_OBJECT_0+1 || rc == WAIT_ABANDONED+1) { 
            Error = broken_pipe;
            ReleaseMutex(Mutex);
        } else { 
            Error = GetLastError();
        }       
        delete sock;
        return NULL;
    }    
    return sock;
}

bool local_win_socket::cancel_accept() 
{
    state = ss_shutdown;
    SetEvent(Signal[RD]);
    SetEvent(Signal[RTT]);
    return true;
}    

char* local_win_socket::get_peer_name()
{
    if (state != ss_open) { 
        Error = not_opened;
        return NULL;
    }
    char* addr = "127.0.0.1";
    char* addr_copy = new char[strlen(addr)+1];
    strcpy(addr_copy, addr);
    Error = ok;
    return addr_copy;
}

bool local_win_socket::is_ok()
{
    return !Error;
}

bool local_win_socket::close()
{
    if (state != ss_close) {            
        state = ss_close;
        if (Mutex) { 
            CloseHandle(Mutex);
        }
        for (int i = RD; i <= RTT; i++) { 
            CloseHandle(Signal[i]);
        }
        UnmapViewOfFile(RcvBuf < SndBuf ? RcvBuf : SndBuf);
        CloseHandle(BufHnd);    
        Error = not_opened;
    }
    return true;
}

void local_win_socket::get_error_text(char* buf, size_t buf_size)
{
    switch (Error) { 
      case ok:
        strncpy(buf, "ok", buf_size-1);
        break;
      case not_opened:
        strncpy(buf, "socket not opened", buf_size-1);
        break;
      case broken_pipe:
        strncpy(buf, "connection is broken", buf_size-1);
        break;
      case timeout_expired:
        strncpy(buf, "connection timeout expired", buf_size-1);
        break;
      default:  
#ifndef PHAR_LAP
        FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM,
                      NULL,
                      Error,
                      0,
                      buf,
                      buf_size-1,
                      NULL);
#else
        strncpy(buf, "Unknown socket error", buf_size-1);
#endif
    }
    buf[buf_size-1] = '\0';
}


bool local_win_socket::shutdown()
{
    if (state == ss_open) { 
        state = ss_shutdown;
        SetEvent(Signal[RD]);   
        SetEvent(Signal[RTT]);  
    }
    return true;
}

bool local_win_socket::connect(int max_attempts, time_t timeout)
{
    char buf[MAX_ADDRESS_LEN];
    int  rc, i, error_code;
    HANDLE h[2];

    for (i = RD; i <= RTT; i++) {  
        sprintf(buf, "%s.%c", Name, ((i + TD - RD) & RTT) + '0');
        Signal[i] = CreateEvent(FASTDB_SECURITY_ATTRIBUTES, false, false, buf);
        if (!Signal[i]) {
            Error = GetLastError();
            while (--i >= 0) { 
                CloseHandle(Signal[i]);
            }
            return false;
        }       
    }
    sprintf(buf, "%s.shr", Name);
    BufHnd = CreateFileMapping(INVALID_HANDLE_VALUE, FASTDB_SECURITY_ATTRIBUTES, PAGE_READWRITE,
                               0, sizeof(socket_buf)*2, buf);
    if (!BufHnd) {
        Error = GetLastError();
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        return false;
    }
    SndBuf = (socket_buf*)MapViewOfFile(BufHnd, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (!SndBuf) { 
        Error = GetLastError();
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        CloseHandle(BufHnd);
        return false;
    }
    RcvBuf = SndBuf+1;
    state = ss_shutdown;
    Mutex = NULL;

    rc = WaitForSingleObject(Signal[RTT],timeout*max_attempts*MILLISECOND);
    if (rc != WAIT_OBJECT_0) {
        error_code = rc == WAIT_TIMEOUT ? timeout_expired : GetLastError();
        close();
        Error = error_code;
        return false;
    }
    connect_data* cdp = (connect_data*)RcvBuf->Data;
    HANDLE hServer = OpenProcess(STANDARD_RIGHTS_REQUIRED|PROCESS_DUP_HANDLE,
                                 false, cdp->Pid);
    if (!hServer) { 
        error_code = GetLastError();
        close();
        Error = error_code;
        return false;
    }
    HANDLE hSelf = GetCurrentProcess();
    if (!DuplicateHandle(hServer, cdp->Mutex, hSelf, &Mutex, 
                         0, false, DUPLICATE_SAME_ACCESS) ||
        !DuplicateHandle(hSelf, WatchDogMutex, hServer, 
                         &((connect_data*)SndBuf->Data)->Mutex, 
                         0, false, DUPLICATE_SAME_ACCESS))
    {
        error_code = GetLastError();
        CloseHandle(hServer);
        close();
        Error = error_code;
        return false;
    }
    SetEvent(Signal[TD]);
    h[0] = Signal[RD];
    h[1] = Mutex;
    rc = WaitForMultipleObjects(2, h, false, INFINITE);

    if (rc != WAIT_OBJECT_0) { 
        if (rc == WAIT_OBJECT_0+1 || rc == WAIT_ABANDONED+1) { 
            error_code = broken_pipe;
            ReleaseMutex(Mutex);
        } else { 
            error_code = GetLastError();
        }
        CloseHandle(hServer);
        close();
        Error = error_code;
        return false;
    }
    accept_data ad = *(accept_data*)RcvBuf->Data;

    SetEvent(Signal[TD]);
    for (i = RD; i <= RTT; i++) { 
        CloseHandle(Signal[i]);
    }
    UnmapViewOfFile(SndBuf);
    CloseHandle(BufHnd);        
    BufHnd = NULL;

    if (!DuplicateHandle(hServer, ad.BufHnd, hSelf, &BufHnd, 
                         0, false, DUPLICATE_SAME_ACCESS))
    {
        Error = GetLastError();
        CloseHandle(hServer);
        CloseHandle(Mutex); 
        return false;
    } else { 
        for (i = RD; i <= RTT; i++) { 
            if (!DuplicateHandle(hServer, ad.Signal[i], 
                                 hSelf, &Signal[i], 
                                 0, false, DUPLICATE_SAME_ACCESS))
            {
                Error = GetLastError();
                CloseHandle(hServer);
                CloseHandle(BufHnd); 
                CloseHandle(Mutex); 
                while (--i >= 0) CloseHandle(Signal[1]);
                return false;
            }
        }
    }
    CloseHandle(hServer);

    SndBuf = (socket_buf*)MapViewOfFile(BufHnd, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (!SndBuf) { 
        Error = GetLastError();
        CloseHandle(BufHnd); 
        CloseHandle(Mutex); 
        for (i = RD; i <= RTT; i++) {  
            CloseHandle(Signal[i]);
        }
        return false;
    }
    RcvBuf = SndBuf+1;
    Error = ok;
    state = ss_open; 
    return true;
}

int local_win_socket::get_handle()
{
    return -1;
}