89 lines
1.8 KiB
Go
89 lines
1.8 KiB
Go
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package manager
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import (
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"errors"
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"log"
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"net/url"
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"reflect"
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"github.com/icedream/irc-medialink/parsers"
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)
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var (
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ErrAlreadyLoaded = errors.New("Already loaded.")
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)
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type Parser interface {
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Init() error
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Name() string
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Parse(u *url.URL, referer *url.URL) parsers.ParseResult
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}
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func (m *Manager) GetParsers() []Parser {
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m.stateLock.RLock()
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defer m.stateLock.RUnlock()
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result := make([]Parser, len(m.registeredParsers))
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copy(result, m.registeredParsers)
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return result
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}
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func (m *Manager) RegisterParser(parser Parser) error {
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m.stateLock.Lock()
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defer m.stateLock.Unlock()
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// Make sure that parser hasn't already been loaded in some way or another
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t := reflect.TypeOf(parser)
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for _, p := range m.registeredParsers {
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if reflect.TypeOf(p) == t {
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return ErrAlreadyLoaded
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}
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}
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// Initialize parser
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log.Printf("Initializing %s parser...", parser.Name())
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if err := parser.Init(); err != nil {
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return err
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}
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m.registeredParsers = append(m.registeredParsers, parser)
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log.Printf("Registered %s parser!", parser.Name())
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return nil
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}
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func (m *Manager) Parse(u *url.URL) (string, parsers.ParseResult) {
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var oldU *url.URL
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attempt := 0
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followLoop:
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for u != nil {
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log.Printf("Parsing %s (referer %s)...", u, oldU)
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attempt++
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if attempt > 15 {
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log.Printf("WARNING: Potential infinite loop for url %s, abort parsing", u)
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break
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}
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for _, p := range m.GetParsers() {
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r := p.Parse(u, oldU)
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if r.Ignored {
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continue
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}
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if r.FollowUrl != nil {
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if *u == *r.FollowUrl {
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log.Printf("WARNING: Ignoring request to follow to same URL, ignoring.")
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break followLoop
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}
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oldU, u = u, r.FollowUrl
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continue followLoop
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}
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return p.Name(), r
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}
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u = nil
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}
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// No parser matches, link ignored
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return "", parsers.ParseResult{
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Ignored: true,
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}
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}
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