readwrite.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
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 * reserved.
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 * modification, are permitted provided that the following conditions
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 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
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 */

#include "win32/fileio.h"
#include "apr_file_io.h"
#include "apr_general.h"
#include "apr_strings.h"
#include "apr_lib.h"
#include "apr_errno.h"
#include <malloc.h>
#include "atime.h"
#include "misc.h"

/*
 * read_with_timeout() 
 * Uses async i/o to emulate unix non-blocking i/o with timeouts.
 */
static apr_status_t read_with_timeout(apr_file_t *file, void *buf, apr_size_t len, apr_size_t *nbytes)
{
    apr_status_t rv;
    *nbytes = 0;

    /* Handle the zero timeout non-blocking case */
    if (file->timeout == 0) {
        /* Peek at the pipe. If there is no data available, return APR_EAGAIN.
         * If data is available, go ahead and read it.
         */
        if (file->pipe) {
            char tmpbuf[5];
            DWORD dwBytesRead;
            DWORD dwBytesAvail;
            DWORD dwBytesLeftThisMsg;
            if (!PeekNamedPipe(file->filehand,         // handle to pipe to copy from
                               &tmpbuf,                   // pointer to data buffer
                               sizeof(tmpbuf),            // size, in bytes, of data buffer
                               &dwBytesRead,           // pointer to number of bytes read
                               &dwBytesAvail,          // pointer to total number of bytes available
                               &dwBytesLeftThisMsg)) { // pointer to unread bytes in this message
                rv = apr_get_os_error();
                if (rv = APR_FROM_OS_ERROR(ERROR_BROKEN_PIPE))
                    return APR_SUCCESS;
            }
            else {
                if (dwBytesRead == 0) {
                    return APR_EAGAIN;
                }
            }
        }
        else {
            /* ToDo: Handle zero timeout non-blocking file i/o 
             * This is not needed until an APR application needs to
             * timeout file i/o (which means setting file i/o non-blocking)
             */
        }
    }

    rv = ReadFile(file->filehand, buf, len, nbytes, file->pOverlapped);

    if (!rv) {
        rv = apr_get_os_error();
        if (rv == APR_FROM_OS_ERROR(ERROR_IO_PENDING)) {
            /* Wait for the pending i/o */
            if (file->timeout > 0) {
                rv = WaitForSingleObject(file->pOverlapped->hEvent, file->timeout/1000); // timeout in milliseconds...
            }
            else if (file->timeout == -1) {
                rv = WaitForSingleObject(file->pOverlapped->hEvent, INFINITE);
            }
            switch (rv) {
            case WAIT_OBJECT_0:
                GetOverlappedResult(file->filehand, file->pOverlapped, nbytes, TRUE);
                rv = APR_SUCCESS;
                break;
            case WAIT_TIMEOUT:
                rv = APR_TIMEUP;
                break;
            case WAIT_FAILED:
                rv = apr_get_os_error();
                break;
            default:
                break;
            }
            if (rv != APR_SUCCESS) {
                CancelIo(file->filehand);
            }
        }
        else if (rv == APR_FROM_OS_ERROR(ERROR_BROKEN_PIPE)) {
            /* Assume ERROR_BROKEN_PIPE signals an EOF reading from a pipe */
            rv = APR_SUCCESS; /* APR_EOF? */
        }
    } else {
        /* OK and 0 bytes read ==> end of file */
        if (*nbytes == 0)
            rv = APR_EOF;
        else
            rv = APR_SUCCESS;
    }
    return rv;
}

APR_DECLARE(apr_status_t) apr_file_read(apr_file_t *thefile, void *buf, apr_size_t *len)
{
    apr_size_t rv;
    DWORD bytes_read = 0;

    if (*len <= 0) {
        *len = 0;
        return APR_SUCCESS;
    }

    /* Handle the ungetchar if there is one */
    if (thefile->ungetchar != -1) {
        bytes_read = 1;
        *(char *)buf = (char)thefile->ungetchar;
        buf = (char *)buf + 1;
        (*len)--;
        thefile->ungetchar = -1;
        if (*len == 0) {
            *len = bytes_read;
            return APR_SUCCESS;
        }
    }
    if (thefile->buffered) {
        char *pos = (char *)buf;
        apr_size_t blocksize;
        apr_size_t size = *len;

        apr_lock_acquire(thefile->mutex);

        if (thefile->direction == 1) {
            apr_file_flush(thefile);
            thefile->bufpos = 0;
            thefile->direction = 0;
            thefile->dataRead = 0;
        }

        rv = 0;
        while (rv == 0 && size > 0) {
            if (thefile->bufpos >= thefile->dataRead) {
                rv = read_with_timeout(thefile, thefile->buffer, 
                                       APR_FILE_BUFSIZE, &thefile->dataRead);
                if (thefile->dataRead == 0) {
                    if (rv == APR_EOF)
                        thefile->eof_hit = TRUE;
                    break;
                }

                thefile->filePtr += thefile->dataRead;
                thefile->bufpos = 0;
            }

            blocksize = size > thefile->dataRead - thefile->bufpos ? thefile->dataRead - thefile->bufpos : size;
            memcpy(pos, thefile->buffer + thefile->bufpos, blocksize);
            thefile->bufpos += blocksize;
            pos += blocksize;
            size -= blocksize;
        }

        *len = pos - (char *)buf;
        if (*len) {
            rv = 0;
        }
        apr_lock_release(thefile->mutex);
    } else {  
        /* Unbuffered i/o */
        apr_size_t nbytes;
        rv = read_with_timeout(thefile, buf, *len, &nbytes);
        *len = nbytes;
    }

    return rv;
}

APR_DECLARE(apr_status_t) apr_file_write(apr_file_t *thefile, const void *buf, apr_size_t *nbytes)
{
    apr_status_t rv;
    DWORD bwrote;

    if (thefile->buffered) {
        char *pos = (char *)buf;
        int blocksize;
        int size = *nbytes;

        apr_lock_acquire(thefile->mutex);

        if (thefile->direction == 0) {
            // Position file pointer for writing at the offset we are logically reading from
            apr_size_t offset = thefile->filePtr - thefile->dataRead + thefile->bufpos;
            if (offset != thefile->filePtr)
                SetFilePointer(thefile->filehand, offset, NULL, FILE_BEGIN);
            thefile->bufpos = thefile->dataRead = 0;
            thefile->direction = 1;
        }

        rv = 0;
        while (rv == 0 && size > 0) {
            if (thefile->bufpos == APR_FILE_BUFSIZE)   // write buffer is full
                rv = apr_file_flush(thefile);

            blocksize = size > APR_FILE_BUFSIZE - thefile->bufpos ? APR_FILE_BUFSIZE - thefile->bufpos : size;
            memcpy(thefile->buffer + thefile->bufpos, pos, blocksize);
            thefile->bufpos += blocksize;
            pos += blocksize;
            size -= blocksize;
        }

        apr_lock_release(thefile->mutex);
        return rv;
    } else {
        if (!thefile->pipe && thefile->append) {
            SetFilePointer(thefile->filehand, 0, NULL, FILE_END);
        }
        if (WriteFile(thefile->filehand, buf, *nbytes, &bwrote, NULL)) {
            *nbytes = bwrote;
            rv = APR_SUCCESS;
        }
        else {
            (*nbytes) = 0;
            rv = apr_get_os_error();
        }
    }

    return rv;
}
/*
 * Too bad WriteFileGather() is not supported on 95&98 (or NT prior to SP2)
 */
APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile,
                                     const struct iovec *vec,
                                     apr_size_t nvec, 
                                     apr_size_t *nbytes)
{
    apr_status_t rv = APR_SUCCESS;
    int i;
    DWORD bwrote = 0;
    char *buf;

    *nbytes = 0;
    for (i = 0; i < nvec; i++) {
        buf = vec[i].iov_base;
        bwrote = vec[i].iov_len;
        rv = apr_file_write(thefile, buf, &bwrote);
        *nbytes += bwrote;
        if (rv != APR_SUCCESS) {
            break;
        }
    }
    return rv;
}

APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile)
{
    DWORD len = 1;

    return apr_file_write(thefile, &ch, &len);
}

APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile)
{
    thefile->ungetchar = (unsigned char) ch;
    return APR_SUCCESS;
}

APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile)
{
    apr_status_t rc;
    int bread;

    bread = 1;
    rc = apr_file_read(thefile, ch, &bread);

    if (rc) {
        return rc;
    }
    
    if (bread == 0) {
        thefile->eof_hit = TRUE;
        return APR_EOF;
    }
    return APR_SUCCESS; 
}

APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile)
{
    DWORD len = strlen(str);

    return apr_file_write(thefile, str, &len);
}

APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, apr_file_t *thefile)
{
    apr_size_t readlen;
    apr_status_t rv = APR_SUCCESS;
    int i;    

    for (i = 0; i < len-1; i++) {
        readlen = 1;
        rv = apr_file_read(thefile, str+i, &readlen);

        if (readlen != 1) {
            rv = APR_EOF;
            break;
        }
        
        if (str[i] == '\r' || str[i] == '\x1A')
            i--; /* don't keep this char */
        else if (str[i] == '\n') {
            i++; /* don't clobber this char below */
            break;
        }
    }
    str[i] = 0;
    return rv;
}

APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile)
{
    if (thefile->buffered) {
        DWORD written = 0;
        apr_status_t rc = 0;

        if (thefile->direction == 1 && thefile->bufpos) {
            if (!WriteFile(thefile->filehand, thefile->buffer, thefile->bufpos, &written, NULL))
                rc = apr_get_os_error();
            thefile->filePtr += written;

            if (rc == 0)
                thefile->bufpos = 0;
        }

        return rc;
    } else {
        FlushFileBuffers(thefile->filehand);
        return APR_SUCCESS;
    }
}

static int printf_flush(apr_vformatter_buff_t *vbuff)
{
    /* I would love to print this stuff out to the file, but I will
     * get that working later.  :)  For now, just return.
     */
    return -1;
}

APR_DECLARE(int) apr_file_printf(apr_file_t *fptr, const char *format, ...)
{
    int cc;
    va_list ap;
    char *buf;
    int len;

    buf = malloc(HUGE_STRING_LEN);
    if (buf == NULL) {
        return 0;
    }
    va_start(ap, format);
    len = apr_vsnprintf(buf, HUGE_STRING_LEN, format, ap);
    cc = apr_file_puts(buf, fptr);
    va_end(ap);
    free(buf);
    return (cc == APR_SUCCESS) ? len : -1;
}