Ejemplo n.º 1
0
// 添加请求值或条目值到列表。
func appendDataList(dataList []base.Data, data base.Data, respDepth uint32) []base.Data {
	if data == nil {
		return dataList
	}
	req, ok := data.(*base.Request)
	if !ok {
		return append(dataList, data)
	}
	newDepth := respDepth + 1
	if req.Depth() != newDepth {
		req = base.NewRequest(req.HttpReq(), newDepth)
	}
	return append(dataList, req)
}
Ejemplo n.º 2
0
// 响应解析函数。只解析“A”标签。
func parseForATag(httpResp *http.Response, respDepth uint32) ([]base.Data, []error) {
	// TODO 支持更多的HTTP响应状态
	if httpResp.StatusCode != 200 {
		err := errors.New(
			fmt.Sprintf("Unsupported status code %d. (httpResponse=%v)", httpResp))
		return nil, []error{err}
	}
	var reqUrl *url.URL = httpResp.Request.URL
	var httpRespBody io.ReadCloser = httpResp.Body
	defer func() {
		if httpRespBody != nil {
			httpRespBody.Close()
		}
	}()
	dataList := make([]base.Data, 0)
	errs := make([]error, 0)
	// 开始解析
	doc, err := goquery.NewDocumentFromReader(httpRespBody)
	if err != nil {
		errs = append(errs, err)
		return dataList, errs
	}
	// 查找“A”标签并提取链接地址
	doc.Find("a").Each(func(index int, sel *goquery.Selection) {
		href, exists := sel.Attr("href")
		// 前期过滤
		if !exists || href == "" || href == "#" || href == "/" {
			return
		}
		href = strings.TrimSpace(href)
		lowerHref := strings.ToLower(href)
		// 暂不支持对Javascript代码的解析。
		if href != "" && !strings.HasPrefix(lowerHref, "javascript") {
			aUrl, err := url.Parse(href)
			if err != nil {
				errs = append(errs, err)
				return
			}
			if !aUrl.IsAbs() {
				aUrl = reqUrl.ResolveReference(aUrl)
			}
			httpReq, err := http.NewRequest("GET", aUrl.String(), nil)
			if err != nil {
				errs = append(errs, err)
			} else {
				req := base.NewRequest(httpReq, respDepth)
				dataList = append(dataList, req)
			}
		}
		text := strings.TrimSpace(sel.Text())
		if text != "" {
			imap := make(map[string]interface{})
			imap["parent_url"] = reqUrl
			imap["a.text"] = text
			imap["a.index"] = index
			item := base.Item(imap)
			dataList = append(dataList, &item)
		}
	})
	return dataList, errs
}
Ejemplo n.º 3
0
func (sched *myScheduler) Start(
	channelArgs base.ChannelArgs,
	poolBaseArgs base.PoolBaseArgs,
	crawlDepth uint32,
	httpClientGenerator GenHttpClient,
	respParsers []anlz.ParseResponse,
	itemProcessors []ipl.ProcessItem,
	firstHttpReq *http.Request) (err error) {
	defer func() {
		if p := recover(); p != nil {
			errMsg := fmt.Sprintf("Fatal Scheduler Error: %s\n", p)
			logger.Fatal(errMsg)
			err = errors.New(errMsg)
		}
	}()
	if atomic.LoadUint32(&sched.running) == 1 {
		return errors.New("The scheduler has been started!\n")
	}
	atomic.StoreUint32(&sched.running, 1)

	if err := channelArgs.Check(); err != nil {
		return err
	}
	sched.channelArgs = channelArgs
	if err := poolBaseArgs.Check(); err != nil {
		return err
	}
	sched.poolBaseArgs = poolBaseArgs
	sched.crawlDepth = crawlDepth

	sched.chanman = generateChannelManager(sched.channelArgs)
	if httpClientGenerator == nil {
		return errors.New("The HTTP client generator list is invalid!")
	}
	dlpool, err :=
		generatePageDownloaderPool(
			sched.poolBaseArgs.PageDownloaderPoolSize(),
			httpClientGenerator)
	if err != nil {
		errMsg :=
			fmt.Sprintf("Occur error when get page downloader pool: %s\n", err)
		return errors.New(errMsg)
	}
	sched.dlpool = dlpool
	analyzerPool, err := generateAnalyzerPool(sched.poolBaseArgs.AnalyzerPoolSize())
	if err != nil {
		errMsg :=
			fmt.Sprintf("Occur error when get analyzer pool: %s\n", err)
		return errors.New(errMsg)
	}
	sched.analyzerPool = analyzerPool

	if itemProcessors == nil {
		return errors.New("The item processor list is invalid!")
	}
	for i, ip := range itemProcessors {
		if ip == nil {
			return errors.New(fmt.Sprintf("The %dth item processor is invalid!", i))
		}
	}
	sched.itemPipeline = generateItemPipeline(itemProcessors)

	if sched.stopSign == nil {
		sched.stopSign = mdw.NewStopSign()
	} else {
		sched.stopSign.Reset()
	}

	sched.reqCache = newRequestCache()
	sched.urlMap = make(map[string]bool)

	sched.startDownloading()
	sched.activateAnalyzers(respParsers)
	sched.openItemPipeline()
	sched.schedule(10 * time.Millisecond)

	if firstHttpReq == nil {
		return errors.New("The first HTTP request is invalid!")
	}
	pd, err := getPrimaryDomain(firstHttpReq.Host)
	if err != nil {
		return err
	}
	sched.primaryDomain = pd

	firstReq := base.NewRequest(firstHttpReq, 0)
	sched.reqCache.put(firstReq)

	return nil
}