| [133] | 1 | |
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| 2 | __all__ = ['Serializer', 'SerializerError'] |
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| 3 | |
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| 4 | from error import YAMLError |
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| 5 | from events import * |
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| 6 | from nodes import * |
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| 7 | |
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| 8 | class SerializerError(YAMLError): |
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| 9 | pass |
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| 10 | |
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| 11 | class Serializer: |
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| 12 | |
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| 13 | ANCHOR_TEMPLATE = u'id%03d' |
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| 14 | |
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| 15 | def __init__(self, emitter, encoding=None, line_break=None, canonical=None, |
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| 16 | indent=None, width=None, allow_unicode=None): |
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| 17 | self.emitter = emitter |
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| 18 | self.serialized_nodes = {} |
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| 19 | self.anchors = {} |
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| 20 | self.last_anchor_id = 0 |
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| 21 | self.closed = None |
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| 22 | self.open(encoding, line_break, canonical, indent, width) |
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| 23 | |
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| 24 | def open(self, encoding=None, line_break=None, canonical=None, |
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| 25 | indent=None, width=None, allow_unicode=None): |
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| 26 | if self.closed is None: |
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| 27 | self.emitter.emit(StreamStartEvent(encoding=encoding, |
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| 28 | line_break=line_break, canonical=canonical, |
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| 29 | indent=indent, width=width, allow_unicode=allow_unicode)) |
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| 30 | self.closed = False |
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| 31 | elif self.closed: |
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| 32 | raise SerializerError("serializer is closed") |
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| 33 | else: |
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| 34 | raise SerializerError("serializer is already opened") |
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| 35 | |
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| 36 | def close(self): |
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| 37 | if self.closed is None: |
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| 38 | raise SerializerError("serializer is not opened") |
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| 39 | elif not self.closed: |
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| 40 | self.emitter.emit(StreamEndEvent()) |
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| 41 | self.closed = True |
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| 42 | |
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| 43 | def __del__(self): |
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| 44 | self.close() |
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| 45 | |
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| 46 | def serialize(self, node, explicit_start=None, explicit_end=None, |
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| 47 | version=None, tags=None): |
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| 48 | if self.closed is None: |
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| 49 | raise SerializerError("serializer is not opened") |
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| 50 | elif self.closed: |
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| 51 | raise SerializerError("serializer is closed") |
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| 52 | self.emitter.emit(DocumentStartEvent(explicit=explicit_start, |
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| 53 | version=version, tags=tags)) |
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| 54 | self.anchor_node(node) |
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| 55 | self.serialize_node(node) |
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| 56 | self.emitter.emit(DocumentEndEvent(explicit=explicit_end)) |
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| 57 | self.serialized_nodes = {} |
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| 58 | self.anchors = {} |
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| 59 | self.last_alias_id = 0 |
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| 60 | |
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| 61 | def anchor_node(self, node): |
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| 62 | if node in self.anchors: |
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| 63 | if self.anchors[node] is None: |
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| 64 | self.anchors[node] = self.generate_anchor(node) |
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| 65 | else: |
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| 66 | self.anchors[node] = None |
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| 67 | if isinstance(node, SequenceNode): |
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| 68 | for item in node.value: |
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| 69 | self.anchor_node(item) |
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| 70 | elif isinstance(node, MappingNode): |
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| 71 | for key in node.value: |
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| 72 | self.anchor_node(key) |
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| 73 | self.anchor_node(node.value[key]) |
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| 74 | |
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| 75 | def generate_anchor(self, node): |
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| 76 | self.last_anchor_id += 1 |
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| 77 | return self.ANCHOR_TEMPLATE % self.last_anchor_id |
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| 78 | |
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| 79 | def serialize_node(self, node): |
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| 80 | alias = self.anchors[node] |
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| 81 | if node in self.serialized_nodes: |
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| 82 | self.emitter.emit(AliasEvent(alias)) |
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| 83 | else: |
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| 84 | self.serialized_nodes[node] = True |
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| 85 | if isinstance(node, ScalarNode): |
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| 86 | self.emitter.emit(ScalarEvent(alias, node.tag, node.value, |
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| 87 | implicit=node.implicit, style=node.style)) |
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| 88 | elif isinstance(node, SequenceNode): |
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| 89 | self.emitter.emit(SequenceStartEvent(alias, node.tag, |
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| 90 | flow_style=node.flow_style)) |
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| 91 | for item in node.value: |
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| 92 | self.serialize_node(item) |
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| 93 | self.emitter.emit(SequenceEndEvent()) |
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| 94 | elif isinstance(node, MappingNode): |
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| 95 | self.emitter.emit(MappingStartEvent(alias, node.tag, |
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| 96 | flow_style=node.flow_style)) |
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| 97 | for key in node.value: |
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| 98 | self.serialize_node(key) |
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| 99 | self.serialize_node(node.value[key]) |
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| 100 | self.emitter.emit(MappingEndEvent()) |
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| 101 | |
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