mod_disk_cache.c

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

    len = sizeof(format);
    apr_file_read_full(dobj->hfd, &format, len, &len);

    if (format == VARY_FORMAT_VERSION) {
        apr_array_header_t* varray;
        apr_time_t expire;

        len = sizeof(expire);
        apr_file_read_full(dobj->hfd, &expire, len, &len);

        varray = apr_array_make(r->pool, 5, sizeof(char*));
        rc = read_array(r, varray, dobj->hfd);
        if (rc != APR_SUCCESS) {
            ap_log_error(APLOG_MARK, APLOG_ERR, rc, r->server,
                         "disk_cache: Cannot parse vary header file: %s",
                         dobj->hdrsfile);
            return DECLINED;
        }
        apr_file_close(dobj->hfd);

        nkey = regen_key(r->pool, r->headers_in, varray, key);

        dobj->hashfile = NULL;
        dobj->prefix = dobj->hdrsfile;
        dobj->hdrsfile = header_file(r->pool, conf, dobj, nkey);

        flags = APR_READ|APR_BINARY|APR_BUFFERED;
        rc = apr_file_open(&dobj->hfd, dobj->hdrsfile, flags, 0, r->pool);
        if (rc != APR_SUCCESS) {
            return DECLINED;
        }
    }
    else if (format != DISK_FORMAT_VERSION) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                     "cache_disk: File '%s' has a version mismatch. File had version: %d.",
                     dobj->hdrsfile, format);
        return DECLINED;
    }
    else {
        apr_off_t offset = 0;
        /* This wasn't a Vary Format file, so we must seek to the
         * start of the file again, so that later reads work.
         */
        apr_file_seek(dobj->hfd, APR_SET, &offset);
        nkey = key;
    }

    obj->key = nkey;
    dobj->key = nkey;
    dobj->name = key;
    dobj->datafile = data_file(r->pool, conf, dobj, nkey);
    dobj->tempfile = apr_pstrcat(r->pool, conf->cache_root, AP_TEMPFILE, NULL);

    /* Open the data file */
    flags = APR_READ|APR_BINARY;
#ifdef APR_SENDFILE_ENABLED
    flags |= APR_SENDFILE_ENABLED;
#endif
    rc = apr_file_open(&dobj->fd, dobj->datafile, flags, 0, r->pool);
    if (rc != APR_SUCCESS) {
        /* XXX: Log message */
        return DECLINED;
    }

    rc = apr_file_info_get(&finfo, APR_FINFO_SIZE, dobj->fd);
    if (rc == APR_SUCCESS) {
        dobj->file_size = finfo.size;
    }

    /* Read the bytes to setup the cache_info fields */
    rc = file_cache_recall_mydata(dobj->hfd, info, dobj, r);
    if (rc != APR_SUCCESS) {
        /* XXX log message */
        return DECLINED;
    }

    /* Initialize the cache_handle callback functions */
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                 "disk_cache: Recalled cached URL info header %s",  dobj->name);
    return OK;
}

static int remove_entity(cache_handle_t *h)
{
    /* Null out the cache object pointer so next time we start from scratch  */
    h->cache_obj = NULL;
    return OK;
}

static int remove_url(cache_handle_t *h, apr_pool_t *p)
{
    apr_status_t rc;
    disk_cache_object_t *dobj;

    /* Get disk cache object from cache handle */
    dobj = (disk_cache_object_t *) h->cache_obj->vobj;
    if (!dobj) {
        return DECLINED;
    }

    /* Delete headers file */
    if (dobj->hdrsfile) {
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                     "disk_cache: Deleting %s from cache.", dobj->hdrsfile);

        rc = apr_file_remove(dobj->hdrsfile, p);
        if ((rc != APR_SUCCESS) && !APR_STATUS_IS_ENOENT(rc)) {
            /* Will only result in an output if httpd is started with -e debug.
             * For reason see log_error_core for the case s == NULL.
             */
            ap_log_error(APLOG_MARK, APLOG_DEBUG, rc, NULL,
                   "disk_cache: Failed to delete headers file %s from cache.",
                         dobj->hdrsfile);
            return DECLINED;
        }
    }

     /* Delete data file */
    if (dobj->datafile) {
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                     "disk_cache: Deleting %s from cache.", dobj->datafile);

        rc = apr_file_remove(dobj->datafile, p);
        if ((rc != APR_SUCCESS) && !APR_STATUS_IS_ENOENT(rc)) {
            /* Will only result in an output if httpd is started with -e debug.
             * For reason see log_error_core for the case s == NULL.
             */
            ap_log_error(APLOG_MARK, APLOG_DEBUG, rc, NULL,
                      "disk_cache: Failed to delete data file %s from cache.",
                         dobj->datafile);
            return DECLINED;
        }
    }

    /* now delete directories as far as possible up to our cache root */
    if (dobj->root) {
        const char *str_to_copy;

        str_to_copy = dobj->hdrsfile ? dobj->hdrsfile : dobj->datafile;
        if (str_to_copy) {
            char *dir, *slash, *q;

            dir = apr_pstrdup(p, str_to_copy);

            /* remove filename */
            slash = strrchr(dir, '/');
            *slash = '\0';

            /*
             * now walk our way back to the cache root, delete everything
             * in the way as far as possible
             *
             * Note: due to the way we constructed the file names in
             * header_file and data_file, we are guaranteed that the
             * cache_root is suffixed by at least one '/' which will be
             * turned into a terminating null by this loop.  Therefore,
             * we won't either delete or go above our cache root.
             */
            for (q = dir + dobj->root_len; *q ; ) {
                 ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, NULL,
                              "disk_cache: Deleting directory %s from cache",
                              dir);

                 rc = apr_dir_remove(dir, p);
                 if (rc != APR_SUCCESS && !APR_STATUS_IS_ENOENT(rc)) {
                    break;
                 }
                 slash = strrchr(q, '/');
                 *slash = '\0';
            }
        }
    }

    return OK;
}

static apr_status_t read_array(request_rec *r, apr_array_header_t* arr,
                               apr_file_t *file)
{
    char w[MAX_STRING_LEN];
    int p;
    apr_status_t rv;

    while (1) {
        rv = apr_file_gets(w, MAX_STRING_LEN - 1, file);
        if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                          "Premature end of vary array.");
            return rv;
        }

        p = strlen(w);
        if (p > 0 && w[p - 1] == '\n') {
            if (p > 1 && w[p - 2] == CR) {
                w[p - 2] = '\0';
            }
            else {
                w[p - 1] = '\0';
            }
        }

        /* If we've finished reading the array, break out of the loop. */
        if (w[0] == '\0') {
            break;
        }

       *((const char **) apr_array_push(arr)) = apr_pstrdup(r->pool, w);
    }

    return APR_SUCCESS;
}

static apr_status_t store_array(apr_file_t *fd, apr_array_header_t* arr)
{
    int i;
    apr_status_t rv;
    struct iovec iov[2];
    apr_size_t amt;
    const char **elts;

    elts = (const char **) arr->elts;

    for (i = 0; i < arr->nelts; i++) {
        iov[0].iov_base = (char*) elts[i];
        iov[0].iov_len = strlen(elts[i]);
        iov[1].iov_base = CRLF;
        iov[1].iov_len = sizeof(CRLF) - 1;

        rv = apr_file_writev(fd, (const struct iovec *) &iov, 2,
                             &amt);
        if (rv != APR_SUCCESS) {
            return rv;
        }
    }

    iov[0].iov_base = CRLF;
    iov[0].iov_len = sizeof(CRLF) - 1;

    return apr_file_writev(fd, (const struct iovec *) &iov, 1,
                         &amt);
}

static apr_status_t read_table(cache_handle_t *handle, request_rec *r,
                               apr_table_t *table, apr_file_t *file)
{
    char w[MAX_STRING_LEN];
    char *l;
    int p;
    apr_status_t rv;

    while (1) {

        /* ### What about APR_EOF? */
        rv = apr_file_gets(w, MAX_STRING_LEN - 1, file);
        if (rv != APR_SUCCESS) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                          "Premature end of cache headers.");
            return rv;
        }

        /* Delete terminal (CR?)LF */

        p = strlen(w);
        /* Indeed, the host's '\n':
           '\012' for UNIX; '\015' for MacOS; '\025' for OS/390
           -- whatever the script generates.
        */
        if (p > 0 && w[p - 1] == '\n') {
            if (p > 1 && w[p - 2] == CR) {
                w[p - 2] = '\0';
            }
            else {
                w[p - 1] = '\0';
            }
        }

        /* If we've finished reading the headers, break out of the loop. */
        if (w[0] == '\0') {
            break;
        }

#if APR_CHARSET_EBCDIC
        /* Chances are that we received an ASCII header text instead of
         * the expected EBCDIC header lines. Try to auto-detect:
         */
        if (!(l = strchr(w, ':'))) {
            int maybeASCII = 0, maybeEBCDIC = 0;
            unsigned char *cp, native;
            apr_size_t inbytes_left, outbytes_left;

            for (cp = w; *cp != '\0'; ++cp) {
                native = apr_xlate_conv_byte(ap_hdrs_from_ascii, *cp);
                if (apr_isprint(*cp) && !apr_isprint(native))
                    ++maybeEBCDIC;
                if (!apr_isprint(*cp) && apr_isprint(native))
                    ++maybeASCII;
            }
            if (maybeASCII > maybeEBCDIC) {
                ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                             "CGI Interface Error: Script headers apparently ASCII: (CGI = %s)",
                             r->filename);
                inbytes_left = outbytes_left = cp - w;
                apr_xlate_conv_buffer(ap_hdrs_from_ascii,
                                      w, &inbytes_left, w, &outbytes_left);
            }
        }
#endif /*APR_CHARSET_EBCDIC*/

        /* if we see a bogus header don't ignore it. Shout and scream */
        if (!(l = strchr(w, ':'))) {
            return APR_EGENERAL;
        }

        *l++ = '\0';
        while (*l && apr_isspace(*l)) {
            ++l;
        }

        apr_table_add(table, w, l);
    }

    return APR_SUCCESS;
}

/*
 * Reads headers from a buffer and returns an array of headers.
 * Returns NULL on file error
 * This routine tries to deal with too long lines and continuation lines.
 * @@@: XXX: FIXME: currently the headers are passed thru un-merged.
 * Is that okay, or should they be collapsed where possible?
 */
static apr_status_t recall_headers(cache_handle_t *h, request_rec *r)
{
    disk_cache_object_t *dobj = (disk_cache_object_t *) h->cache_obj->vobj;

    /* This case should not happen... */
    if (!dobj->hfd) {
        /* XXX log message */
        return APR_NOTFOUND;
    }

    h->req_hdrs = apr_table_make(r->pool, 20);
    h->resp_hdrs = apr_table_make(r->pool, 20);

    /* Call routine to read the header lines/status line */
    read_table(h, r, h->resp_hdrs, dobj->hfd);
    read_table(h, r, h->req_hdrs, dobj->hfd);

    apr_file_close(dobj->hfd);

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                 "disk_cache: Recalled headers for URL %s",  dobj->name);
    return APR_SUCCESS;
}

static apr_status_t recall_body(cache_handle_t *h, apr_pool_t *p, apr_bucket_brigade *bb)
{
    apr_bucket *e;
    disk_cache_object_t *dobj = (disk_cache_object_t*) h->cache_obj->vobj;

    e = apr_bucket_file_create(dobj->fd, 0, (apr_size_t) dobj->file_size, p,
                               bb->bucket_alloc);
    APR_BRIGADE_INSERT_HEAD(bb, e);
    e = apr_bucket_eos_create(bb->bucket_alloc);
    APR_BRIGADE_INSERT_TAIL(bb, e);

    return APR_SUCCESS;
}

static apr_status_t store_table(apr_file_t *fd, apr_table_t *table)
{
    int i;
    apr_status_t rv;
    struct iovec iov[4];
    apr_size_t amt;
    apr_table_entry_t *elts;

    elts = (apr_table_entry_t *) apr_table_elts(table)->elts;
    for (i = 0; i < apr_table_elts(table)->nelts; ++i) {
        if (elts[i].key != NULL) {
            iov[0].iov_base = elts[i].key;
            iov[0].iov_len = strlen(elts[i].key);
            iov[1].iov_base = ": ";
            iov[1].iov_len = sizeof(": ") - 1;
            iov[2].iov_base = elts[i].val;
            iov[2].iov_len = strlen(elts[i].val);
            iov[3].iov_base = CRLF;
            iov[3].iov_len = sizeof(CRLF) - 1;

            rv = apr_file_writev(fd, (const struct iovec *) &iov, 4,
                                 &amt);
            if (rv != APR_SUCCESS) {
                return rv;
            }
        }
    }
    iov[0].iov_base = CRLF;
    iov[0].iov_len = sizeof(CRLF) - 1;