Annotation of libwww/Library/src/HTChannl.c, revision 2.5

2.1       frystyk     1: /*                                                                  HTChannl.c
                      2: **     CONTAINS STREAMS FOR READING AND WRITING TO AND FROM A TRANSPORT
                      3: **
                      4: **     (c) COPYRIGHT MIT 1995.
                      5: **     Please first read the full copyright statement in the file COPYRIGH.
2.5     ! frystyk     6: **     @(#) $Id: HTChannl.c,v 2.4 1996/05/20 15:06:28 frystyk Exp $
2.1       frystyk     7: **
                      8: **
                      9: ** HISTORY:
                     10: **     April 96  HFN   Written
                     11: */
                     12: 
                     13: /* Library Include files */
                     14: #include "sysdep.h"
                     15: #include "WWWUtil.h"
                     16: #include "HTAlert.h"
                     17: #include "HTError.h"
                     18: #include "HTChannl.h"                                   /* Implemented here */
                     19: 
                     20: #define HASH_SIZE      67
                     21: #define HASH(s)                ((s) % HASH_SIZE)
                     22: 
                     23: struct _HTChannel {
                     24:     SOCKET             sockfd;                                    /* Socket */
                     25:     FILE *             fp;
                     26:     HTChannelMode      mode;                             /* Mode of channel */
                     27:     HTInputStream *    input;                               /* Input stream */
                     28:     HTOutputStream *   output;                             /* Output stream */
                     29:     BOOL               active;                 /* Active or passive channel */
                     30:     int                        semaphore;                         /* On channel use */
                     31: };
                     32: 
                     33: struct _HTInputStream {
                     34:     const HTInputStreamClass * isa;    
                     35: };
                     36: 
                     37: struct _HTOutputStream {
                     38:     const HTOutputStreamClass *        isa;    
                     39: };
                     40: 
                     41: PRIVATE HTList ** channels = NULL;                      /* List of channels */
                     42: 
                     43: /* ------------------------------------------------------------------------- */
                     44: 
                     45: PRIVATE void free_channel (HTChannel * ch)
                     46: {
                     47:     if (ch) {
                     48: 
                     49:        /* Close the input and output stream */
                     50:        if (ch->input) (*ch->input->isa->close)(ch->input);
                     51:        if (ch->output) (*ch->output->isa->close)(ch->output);
                     52: 
                     53:        /* Close the socket */
                     54:        if (ch->sockfd != INVSOC) {
                     55:            NETCLOSE(ch->sockfd);
2.3       eric       56:            HTEvent_unregister(ch->sockfd, (SockOps) FD_ALL);
2.1       frystyk    57:            if (PROT_TRACE)
                     58:                HTTrace("Channel..... Deleted %p, socket %d\n", ch,ch->sockfd);
                     59:        }
                     60: 
                     61:        /* Close the file */
                     62:        if (ch->fp) {
                     63:            fclose(ch->fp);
                     64:            if (PROT_TRACE)
                     65:                HTTrace("Channel..... Deleted %p, file %p\n", ch, ch->fp);
                     66:        }
                     67:        HT_FREE(ch);
                     68:     }
                     69: }
                     70: 
                     71: /*
                     72: **     A channel is uniquely identified by a socket.
                     73: **     Note that we don't create the input and output stream - they are 
                     74: **     created later. When a channel first is created it has the default mode
                     75: **     HT_CH_SINGLE which ensures that other connections to the same host
                     76: **     will not result in multiple parallel connections but wait and see if
                     77: **     the actual mode supported by the peer process.
                     78: **
                     79: **     We only keep a hash on sockfd's as we don't have to look for channels
                     80: **     for ANSI file descriptors.
                     81: */
                     82: PUBLIC HTChannel * HTChannel_new (HTNet * net, BOOL active)
                     83: {
                     84:     if (net) {
                     85:        HTList * list = NULL;
                     86:        HTChannel * ch = NULL;
2.5     ! frystyk    87:        SOCKET sockfd = HTNet_socket(net);
        !            88:        int hash = sockfd < 0 ? 0 : HASH(sockfd);
2.1       frystyk    89:        if (PROT_TRACE) HTTrace("Channel..... Hash value is %d\n", hash);
                     90:        if (!channels) {
                     91:            if (!(channels = (HTList **) HT_CALLOC(HASH_SIZE,sizeof(HTList*))))
                     92:                HT_OUTOFMEM("HTChannel_new");
                     93:        }
                     94:        if (!channels[hash]) channels[hash] = HTList_new();
                     95:        list = channels[hash];
                     96:        if ((ch = (HTChannel *) HT_CALLOC(1, sizeof(HTChannel))) == NULL)
                     97:            HT_OUTOFMEM("HTChannel_new");           
2.5     ! frystyk    98:        ch->sockfd = sockfd;
2.1       frystyk    99:        ch->mode = HT_CH_SINGLE;
                    100:        ch->active = active;
                    101:        ch->semaphore = 1;
                    102:        HTList_addObject(list, (void *) ch);
                    103:        if (PROT_TRACE) HTTrace("Channel..... Added %p to list %p\n", ch,list);
                    104:        return ch;
                    105:     }
                    106:     return NULL;
                    107: }
                    108: 
                    109: /*
                    110: **     Look for a channel object if we for some reason should have lost it
                    111: **     Returns NULL if nothing found
                    112: */
                    113: PUBLIC HTChannel * HTChannel_find (SOCKET sockfd)
                    114: {
                    115:     if (channels && sockfd != INVSOC) {
                    116:        int hash = HASH(sockfd);
                    117:        HTList * list = channels[hash];
                    118:        if (list) {
                    119:            HTChannel * ch = NULL;
                    120:            while ((ch = (HTChannel *) HTList_nextObject(list)))
                    121:                if (ch->sockfd == sockfd) return ch;
                    122:        }
                    123:     }
                    124:     return NULL;
                    125: }
                    126: 
                    127: /*
                    128: **     When deleting a channel we first look at if there are no more requests
                    129: **     using the channel (the semaphore is <= 0). Then, if the socket supports
                    130: **     persistent connections then we register the channel in the Host cache
                    131: **     and wait until the other end closes it or we get a time out on our side
                    132: */
                    133: PUBLIC BOOL HTChannel_delete (HTChannel * channel)
                    134: {
                    135:     if (channel) {
2.2       frystyk   136:        if (PROT_TRACE) HTTrace("Channel..... Delete %p with semaphore %d\n",
2.1       frystyk   137:                                channel, channel->semaphore);
                    138:        /*
                    139:        **  We call the free methods on both the input stream and the output
                    140:        **  stream so that we can free up the stream pipes. However, note that
                    141:        **  this doesn't mean that we close the input stream and output stream
                    142:        **  them selves - only the generic streams
                    143:        */
                    144:        if (channel->input) (*channel->input->isa->_free)(channel->input);
                    145:        if (channel->output) (*channel->output->isa->_free)(channel->output);
                    146: 
                    147:        /*
                    148:        **  Check whether this channel is used by other objects or we can
                    149:        **  delete it and free memory.
                    150:        */
                    151:        if (channel->semaphore <= 0 && channels) {
                    152:            int hash = HASH(channel->sockfd);
                    153:            HTList * list = channels[hash];
                    154:            if (list) {
                    155:                HTList_removeObject(list, (void *) channel);
                    156:                free_channel(channel);
                    157:                return YES;
                    158:            }
                    159:        }
                    160:     }
                    161:     return NO;
                    162: }
                    163: 
                    164: /*     HTChannel_deleteAll
                    165: **     -------------------
                    166: **     Destroys all channels. This is called by HTLibTerminate(0
                    167: */
                    168: PUBLIC BOOL HTCannel_deleteAll (void)
                    169: {
                    170:     if (channels) {
                    171:        HTList * cur;
                    172:        int cnt;
                    173:        for (cnt=0; cnt<HASH_SIZE; cnt++) {
                    174:            if ((cur = channels[cnt])) { 
                    175:                HTChannel * pres;
                    176:                while ((pres = (HTChannel *) HTList_nextObject(cur)) != NULL)
                    177:                    free_channel(pres);
                    178:            }
                    179:            HTList_delete(channels[cnt]);
                    180:        }
                    181:        HT_FREE(channels);
                    182:     }
                    183:     return YES;
                    184: }
                    185: 
                    186: /*
                    187: **     Set and get the mode of a channel. A channel may change mode in the 
                    188: **     middle of a connection. We also return whether the channel is active
                    189: **     or passive.
                    190: */
                    191: PUBLIC HTChannelMode HTChannel_mode (HTChannel * channel, BOOL * active)
                    192: {
                    193:     return channel ? channel->mode : HT_CH_SINGLE;
                    194: }
                    195: 
                    196: PUBLIC BOOL HTChannel_setMode (HTChannel * channel, HTChannelMode mode)
                    197: {
                    198:     if (channel) {
                    199:        channel->mode = mode;
                    200:        return YES;
                    201:     }
                    202:     return NO;
                    203: }
                    204: 
                    205: /*
                    206: **     Check whether a channel is idle meaning if it is ready for a new
                    207: **     request which depends on the mode of the channel. If the channel is 
                    208: **     idle, i.e. ready for use then return YES else NO.
                    209: */
                    210: PUBLIC BOOL HTChannel_idle (HTChannel * channel)
                    211: {
                    212:     return (channel &&
                    213:            ((channel->mode != HT_CH_SINGLE) ||
                    214:             (channel->mode == HT_CH_SINGLE && channel->semaphore <= 0)));
                    215: }
                    216: 
                    217: /*
                    218: **     Return the socket associated with this channel
                    219: */
                    220: PUBLIC SOCKET HTChannel_socket (HTChannel * channel)
                    221: {
                    222:     return channel ? channel->sockfd : INVSOC;
2.4       frystyk   223: }
                    224: 
                    225: /*
                    226: **     Return the file descriptor associated with this channel
                    227: */
                    228: PUBLIC FILE * HTChannel_file (HTChannel * channel)
                    229: {
                    230:     return channel ? channel->fp : NULL;
2.1       frystyk   231: }
                    232: 
                    233: /*
                    234: **     Increase the semaphore for this channel
                    235: */
                    236: PUBLIC void HTChannel_upSemaphore (HTChannel * channel)
                    237: {
                    238:     if (channel) {
                    239:        channel->semaphore++;
                    240:        if (PROT_TRACE)
                    241:            HTTrace("Channel..... Semaphore increased to %d for channel %p\n",
                    242:                    channel->semaphore, channel);
                    243:     }
                    244: }
                    245: 
                    246: /*
                    247: **     Decrease the semaphore for this channel
                    248: */
                    249: PUBLIC void HTChannel_downSemaphore (HTChannel * channel)
                    250: {
                    251:     if (channel) {
                    252:        channel->semaphore--;
                    253:        if (channel->semaphore <= 0) channel->semaphore = 0;
                    254:        if (PROT_TRACE)
                    255:            HTTrace("Channel..... Semaphore decreased to %d for channel %p\n",
                    256:                    channel->semaphore, channel);
                    257:     }
                    258: }
                    259: 
                    260: /*
                    261: **     Create the input stream and bind it to the channel
                    262: **     Please read the description in the HTIOStream module on the parameters
                    263: */
                    264: PUBLIC BOOL HTChannel_setInput (HTChannel * ch,
                    265:                                HTInputStream * input, HTChannelMode mode)
                    266: {
                    267:     if (ch) {
                    268:        ch->mode = mode;
                    269:        ch->input = input;
                    270:        return YES;
                    271:     }
                    272:     return NO;
                    273: }
                    274: 
                    275: PUBLIC HTInputStream * HTChannel_input (HTChannel * ch)
                    276: {
                    277:     return ch ? ch->input : NULL;
                    278: }
                    279: 
                    280: /*
                    281: **     Create the output stream and bind it to the channel
                    282: **     Please read the description in the HTIOStream module on the parameters
                    283: */
                    284: PUBLIC BOOL HTChannel_setOutput (HTChannel * ch,
                    285:                                 HTOutputStream * output, HTChannelMode mode)
                    286: {
                    287:     if (ch) {
                    288:        ch->mode = mode;
                    289:        ch->output = output;
                    290:        return YES;
                    291:     }
                    292:     return NO;
                    293: }
                    294: 
                    295: PUBLIC HTOutputStream * HTChannel_output (HTChannel * ch)
                    296: {
                    297:     return ch ? ch->output : NULL;
                    298: }
                    299: 

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