/*
 * $Id: wais.c,v 1.138 2001/10/24 08:19:09 hno Exp $
 *
 * DEBUG: section 24    WAIS Relay
 * AUTHOR: Harvest Derived
 *
 * SQUID Web Proxy Cache          http://www.squid-cache.org/
 * ----------------------------------------------------------
 */
#include "squidDeclaration.h"

#include "squid.h"

typedef struct {
    int fd;
    StoreEntry *entry;
    method_t method;
    const HttpHeader *request_hdr;
    char url[MAX_URL];
    request_t *request;
    FwdState *fwd;
} WaisStateData;

static PF waisStateFree;
static PF waisTimeout;
static PF waisReadReply;
static CWCB waisSendComplete;
static PF waisSendRequest;

static void
waisStateFree(int fdnotused, void *data)
{
    WaisStateData *waisState = (WaisStateData *)data;
    if (waisState == NULL)
       return;
    storeUnlockObject(waisState->entry);
    requestUnlink(waisState->request);
    cbdataFree(waisState,WaisStateData);
}

/* This will be called when socket lifetime is expired. */
static void
waisTimeout(int fd, void *data)
{
    WaisStateData *waisState = (WaisStateData *)data;
    StoreEntry *entry = waisState->entry;
    debug(24, 4) ("waisTimeout: FD %d: '%s'\n", fd, storeUrl(entry));
    if (entry->store_status == STORE_PENDING) {
       if (entry->mem_obj->inmem_hi == 0) {
           fwdFail(waisState->fwd,
               errorCon(ERR_READ_TIMEOUT, HTTP_GATEWAY_TIMEOUT));
       }
    }
    comm_close(fd);
}

/* This will be called when data is ready to be read from fd.  Read until
 * error or connection closed. */
static void
waisReadReply(int fd, void *data)
{
    WaisStateData *waisState = (WaisStateData *)data;
    LOCAL_ARRAY(char, buf, 4096);
    StoreEntry *entry = waisState->entry;
    int len;
    int clen;
    int bin;
    size_t read_sz;
#if DELAY_POOLS
    Delay_id delay_id = delayMostBytesAllowed(entry->mem_obj);
#endif
    if (EBIT_TEST(entry->flags, ENTRY_ABORTED)) {
       comm_close(fd);
       return;
    }
    errno = 0;
    read_sz = 4096;
#if DELAY_POOLS
    read_sz = delayBytesWanted(delay_id, 1, read_sz);
#endif
    statCounter.syscalls.sock.reads++;
    len = squid_fd_table.fd_table[fd].read(buf, read_sz);
    if (len > 0) {
//       fd_bytes(fd, len, FD_READ);
#if DELAY_POOLS
       delayBytesIn(delay_id, len);
#endif
       kb_incr(&statCounter.server.all.kbytes_in, len);
       kb_incr(&statCounter.server.other.kbytes_in, len);
    }
    debug(24, 5) ("waisReadReply: FD %d read len:%d\n", fd, len);
    if (len > 0) {
       commSetTimeout(fd, Config.Timeout.read, NULL, NULL);
       IOStats.Wais.reads++;
       for (clen = len - 1, bin = 0; clen; bin++)
           clen >>= 1;
       IOStats.Wais.read_hist[bin]++;
    }
    if (len < 0) {
       debug(50, 1) ("waisReadReply: FD %d: read failure: %s.\n",
           fd, xstrerror_type(squid_fd_table.fd_table[fd].type));
       if (ignoreErrno(errno,squid_fd_table.fd_table[fd].type)) {
           /* reinstall handlers */
           /* XXX This may loop forever */
           commSetSelect(fd, COMM_SELECT_READ,
               waisReadReply, waisState, 0);
       } else {
           ErrorState *err;
           EBIT_CLR(entry->flags, ENTRY_CACHABLE);
           storeReleaseRequest(entry);
           err = errorCon(ERR_READ_ERROR, HTTP_INTERNAL_SERVER_ERROR);
#ifdef _SQUID_OS2VAC_
       err->xerrno = sock_errno();
#else
       err->xerrno = errno;
#endif
           err->request = requestLink(waisState->request);
           errorAppendEntry(entry, err);
           comm_close(fd);
       }
    } else if (len == 0 && entry->mem_obj->inmem_hi == 0) {
       ErrorState *err;
       err = errorCon(ERR_ZERO_SIZE_OBJECT, HTTP_SERVICE_UNAVAILABLE);
#ifdef _SQUID_OS2VAC_
       err->xerrno = sock_errno();
#else
       err->xerrno = errno;
#endif
       err->request = requestLink(waisState->request);
       errorAppendEntry(entry, err);
       comm_close(fd);
    } else if (len == 0) {
       /* Connection closed; retrieval done. */
       entry->expires = squid_curtime;
       fwdComplete(waisState->fwd);
       comm_close(fd);
    } else {
       storeAppend(entry, buf, len);
       commSetSelect(fd,
           COMM_SELECT_READ,
           waisReadReply,
           waisState, 0);
    }
}

/* This will be called when request write is complete. Schedule read of
 * reply. */
static void
waisSendComplete(int fd, char *bufnotused, size_t size, int errflag, void *data)
{
    WaisStateData *waisState = (WaisStateData *)data;
    StoreEntry *entry = waisState->entry;
    debug(24, 5) ("waisSendComplete: FD %d size: %d errflag: %d\n",
       fd, (int) size, errflag);
    if (size > 0) {
       //fd_bytes(fd, size, FD_WRITE);
       kb_incr(&statCounter.server.all.kbytes_out, size);
       kb_incr(&statCounter.server.other.kbytes_out, size);
    }
    if (errflag == COMM_ERR_CLOSING)
       return;
    if (errflag) {
       ErrorState *err;
       err = errorCon(ERR_WRITE_ERROR, HTTP_SERVICE_UNAVAILABLE);
#ifdef _SQUID_OS2VAC_
       err->xerrno = sock_errno();
#else
       err->xerrno = errno;
#endif
       err->request = requestLink(waisState->request);
       errorAppendEntry(entry, err);
       comm_close(fd);
    } else {
       /* Schedule read reply. */
       commSetSelect(fd,
           COMM_SELECT_READ,
           waisReadReply,
           waisState, 0);
       commSetDefer(fd, fwdCheckDeferRead, entry);
    }
}

/* This will be called when connect completes. Write request. */
static void
waisSendRequest(int fd, void *data)
{
    WaisStateData *waisState = (WaisStateData *)data;
    MemBuf mb;
    const char *Method = RequestMethodStr[waisState->method];
    debug(24, 5) ("waisSendRequest: FD %d\n", fd);
    memBufDefInit(&mb);
    memBufPrintf(&mb, "%s %s HTTP/1.0\r\n", Method, waisState->url);
    if (waisState->request_hdr) {
       Packer p;
       packerToMemInit(&p, &mb);
       httpHeaderPackInto(waisState->request_hdr, &p);
       packerClean(&p);
    }
    memBufPrintf(&mb, "\r\n");
    debug(24, 6) ("waisSendRequest: buf: %s\n", mb.buf);
    comm_write_mbuf(fd, mb, waisSendComplete, waisState);
    if (EBIT_TEST(waisState->entry->flags, ENTRY_CACHABLE))
       storeSetPublicKey(waisState->entry);    /* Make it public */
    EBIT_CLR(waisState->entry->flags, ENTRY_FWD_HDR_WAIT);
}

CBDATA_TYPE(WaisStateData);
void
waisStart(FwdState * fwd)
{
    WaisStateData *waisState = NULL;
    request_t *request = fwd->request;
    StoreEntry *entry = fwd->entry;
    int fd = fwd->server_fd;
    const char *url = storeUrl(entry);
    method_t method = request->method;
    debug(24, 3) ("waisStart: \"%s %s\"\n", RequestMethodStr[method], url);
    statCounter.server.all.requests++;
    statCounter.server.other.requests++;
    CBDATA_INIT_TYPE(WaisStateData);
    waisState = cbdataAlloc(WaisStateData);
    waisState->method = method;
    waisState->request_hdr = &request->header;
    waisState->fd = fd;
    waisState->entry = entry;
    xstrncpy(waisState->url, url, MAX_URL);
    waisState->request = requestLink(request);
    waisState->fwd = fwd;
    comm_add_close_handler(waisState->fd, waisStateFree, waisState);
    storeLockObject(entry);
    commSetSelect(fd, COMM_SELECT_WRITE, waisSendRequest, waisState, 0);
    commSetTimeout(fd, Config.Timeout.read, waisTimeout, waisState);
}
