forked from Silverfish/proton-bridge
94 lines
2.6 KiB
Go
94 lines
2.6 KiB
Go
// Copyright (c) 2020 Proton Technologies AG
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//
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// This file is part of ProtonMail Bridge.
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//
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// ProtonMail Bridge is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// ProtonMail Bridge is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with ProtonMail Bridge. If not, see <https://www.gnu.org/licenses/>.
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package parser
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import "regexp"
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type Walker struct {
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root *Part
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handlers []*handler
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defaultHandler HandlerFunc
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}
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func newWalker(root *Part) *Walker {
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return &Walker{
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root: root,
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defaultHandler: func(*Part) error { return nil },
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}
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}
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func (w *Walker) Walk() (err error) {
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return w.walkOverPart(w.root)
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}
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func (w *Walker) walkOverPart(p *Part) error {
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if err := w.getHandlerFunc(p)(p); err != nil {
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return err
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}
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for _, child := range p.children {
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if err := w.walkOverPart(child); err != nil {
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return err
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}
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}
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return nil
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}
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// RegisterDefaultHandler registers a handler that will be called on every part
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// that doesn't match a registered content type/disposition handler.
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func (w *Walker) RegisterDefaultHandler(fn HandlerFunc) *Walker {
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w.defaultHandler = fn
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return w
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}
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// RegisterContentTypeHandler registers a handler that will be called when a
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// part's content type matches the given regular expression.
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// If a part matches multiple handlers, the one registered first will be chosen.
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func (w *Walker) RegisterContentTypeHandler(typeRegExp string, fn HandlerFunc) *Walker {
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w.handlers = append(w.handlers, &handler{
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typeRegExp: regexp.MustCompile(typeRegExp),
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fn: fn,
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})
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return w
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}
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// RegisterContentDispositionHandler registers a handler that will be called
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// when a part's content disposition matches the given regular expression.
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// If a part matches multiple handlers, the one registered first will be chosen.
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func (w *Walker) RegisterContentDispositionHandler(dispRegExp string, fn HandlerFunc) *Walker {
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w.handlers = append(w.handlers, &handler{
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dispRegExp: regexp.MustCompile(dispRegExp),
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fn: fn,
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})
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return w
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}
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func (w *Walker) getHandlerFunc(p *Part) HandlerFunc {
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for _, handler := range w.handlers {
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if handler.matchPart(p) {
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return handler.fn
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}
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}
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return w.defaultHandler
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}
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