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/*

 * Copyright (c) 1999 Greg Haerr <greg@censoft.com>

 *

 * Nano-X Core Protocol Client Request Handling Routines

 */

#include <stdio.h>

#include <unistd.h>

#include <stdlib.h>

#include <assert.h>

#include <errno.h>

#include <string.h>

#include "serv.h"

#include "nxproto.h"

#define SZREQBUF        2048    /* initial request buffer size*/

#ifndef __ECOS

static REQBUF   reqbuf;         /* request buffer*/

extern int      nxSocket;

extern char *   nxSharedMem;

#endif

/* Allocate a request buffer of passed size and fill in header fields*/

void *

nxAllocReq(int type, long size, long extra)

{

        nxReq * req;

        long    aligned_len;

        ACCESS_PER_THREAD_DATA();

        /* variable size requests must be hand-padded*/

        if(extra)

                assert((size & (long)(ALIGNSZ-1)) == 0);

        /* calculate aligned length of request buffer*/

        aligned_len = (size + extra + (long)(ALIGNSZ-1)) & ~(long)(ALIGNSZ-1);

        /* verify we're not greater than max request size*/

        assert(aligned_len <= MAXREQUESTSZ);

        /* flush buffer if required, and allocate larger one if required*/

        if(reqbuf.bufptr + aligned_len >= reqbuf.bufmax)

                nxFlushReq(aligned_len,1);

        /* fill in request header*/

        req = (nxReq *)reqbuf.bufptr;

        req->reqType = (BYTE8)type;

        req->hilength = (BYTE8)((size + extra) >> 16);

        req->length = (UINT16)(size + extra);

        reqbuf.bufptr += aligned_len;

        return req;

}

static void nxAllocReqbuffer(long newsize)

{

        ACCESS_PER_THREAD_DATA();

        if(newsize < (long)SZREQBUF)

                newsize = SZREQBUF;

        reqbuf.buffer = malloc(newsize);

        if(!reqbuf.buffer) {

                EPRINTF("nxFlushReq: Can't allocate initial request buffer\n");

                exit(1);

        }

        reqbuf.bufptr = reqbuf.buffer;

        reqbuf.bufmax = reqbuf.buffer + newsize;

}

void

nxAssignReqbuffer(char *buffer, long size)

{

        ACCESS_PER_THREAD_DATA();

        if ( reqbuf.buffer != 0 )

                free(reqbuf.buffer);

        reqbuf.buffer = buffer;

        reqbuf.bufptr = reqbuf.buffer;

        reqbuf.bufmax = reqbuf.buffer + size;

}

/* Write a block of data on the socket to the nano-X server */

void

nxWriteSocket(char *buf, int todo)

{

        int written;

        ACCESS_PER_THREAD_DATA();

        do {

                written = write(nxSocket, buf, todo);

                if ( written < 0 ) {

                        if ( errno == EAGAIN || errno == EINTR )

                                continue;

                        EPRINTF("nxFlushReq: write failed: %m\n");

                        exit(1);

                }

                buf += written;

                todo -= written;

        } while ( todo > 0 );

}

/* Flush request buffer if required, possibly reallocate buffer size*/

void

nxFlushReq(long newsize, int reply_needed)

{

        ACCESS_PER_THREAD_DATA();

        /* handle one-time initialization case*/

        if(reqbuf.buffer == NULL) {

                nxAllocReqbuffer(newsize);

                return;

        }

        /* flush buffer if required*/

        if(reqbuf.bufptr > reqbuf.buffer) {

                char *  buf = reqbuf.buffer;

                int     todo = reqbuf.bufptr - reqbuf.buffer;

#if HAVE_SHAREDMEM_SUPPORT

                if ( nxSharedMem != 0 ) {

                        /* There is a shared memory segment used for the

                         * request buffer.  Make up a flush command and

                         * send it over the socket, to tell the server to

                         * process the shared memory segment.

                         * The 'reply_needed' argument should be non-zero

                         * when a confirmation is needed that all commands

                         * are flushed, so new ones can be filled into the

                         * request buffer.  NOTE:  This is *only* needed

                         * when explicitely flushing the request buffer, or

                         * when flushing it to make space for new commands.

                         * DO NOT REQUEST A REPLY when flushing the request

                         * buffer because the last command in the buffer

                         * will send a response:  This response would be

                         * queued up first and had to be drained before the

                         * response to the flush command itsel....

                         * So the GrReadBlock used to read replys to commands

                         * must not specify a nonzero 'reply_needed'.

                         * Not requesting a reply in this case is

                         * safe, since the command executed will wait for

                         * the reply *it* is waiting for, and thus make

                         * sure the request buffer is flushed before

                         * continuing.

                         *

                         * We have to make the protocol request by hand,

                         * as it has to be sent over the socket to wake

                         * up the Nano-X server.

                         */

                        char c;

                        nxShmCmdsFlushReq req;

                        req.reqType = GrNumShmCmdsFlush;

                        req.hilength = 0;

                        req.length = sizeof(req);

                        req.size = todo;

                        req.reply = reply_needed;

                        nxWriteSocket((char *)&req,sizeof(req));

                        if ( reply_needed )

                                while ( read(nxSocket, &c, 1) != 1 )

                                        ;

                        reqbuf.bufptr = reqbuf.buffer;

                        if ( reqbuf.buffer + newsize > reqbuf.bufmax ) {

                                /* Shared memory too small, critical */

                                EPRINTF("nxFlushReq: shm region too small\n");

                                exit(1);

                        }

                        return;

                }

#endif /* HAVE_SHAREDMEM_SUPPORT*/

                /* Standard Socket transfer */

                nxWriteSocket(buf,todo);

                reqbuf.bufptr = reqbuf.buffer;

        }

        /* allocate larger buffer for current request, if needed*/

        if(reqbuf.bufptr + newsize >= reqbuf.bufmax) {

                reqbuf.buffer = realloc(reqbuf.buffer, newsize);

                if(!reqbuf.buffer) {

                       EPRINTF("nxFlushReq: Can't reallocate request buffer\n");

                        exit(1);

                }

                reqbuf.bufptr = reqbuf.buffer;

                reqbuf.bufmax = reqbuf.buffer + newsize;

        }

}

/* calc # bytes required for passed string according to encoding*/

int

nxCalcStringBytes(void *str, int count, int flags)

{

        int     nbytes;

        /* calc byte length of data*/

        if(flags & MWTF_UC16)

                nbytes = count * 2;

        else if(flags & MWTF_UC32)

                nbytes = count * 4;

        else

                nbytes = count;

        return nbytes;

}