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1 | // Licensed to the Apache Software Foundation (ASF) under one |
2 | // or more contributor license agreements. See the NOTICE file | |
3 | // distributed with this work for additional information | |
4 | // regarding copyright ownership. The ASF licenses this file | |
5 | // to you under the Apache License, Version 2.0 (the | |
6 | // "License"); you may not use this file except in compliance | |
7 | // with the License. You may obtain a copy of the License at | |
8 | // | |
9 | // http://www.apache.org/licenses/LICENSE-2.0 | |
10 | // | |
11 | // Unless required by applicable law or agreed to in writing, software | |
12 | // distributed under the License is distributed on an "AS IS" BASIS, | |
13 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
14 | // See the License for the specific language governing permissions and | |
15 | // limitations under the License. | |
16 | ||
17 | package schema | |
18 | ||
19 | import ( | |
20 | "github.com/apache/arrow/go/v6/parquet" | |
21 | "golang.org/x/xerrors" | |
22 | ) | |
23 | ||
24 | // ListOf is a convenience helper function to create a properly structured | |
25 | // list structure according to the Parquet Spec. | |
26 | // | |
27 | // <list-repetition> group <name> (LIST) { | |
28 | // repeated group list { | |
29 | // <element-repetition> <element-type> element; | |
30 | // } | |
31 | // } | |
32 | // | |
33 | // <list-repetition> can only be optional or required. panics if repeated. | |
34 | // <element-repetition> can only be optional or required. panics if repeated. | |
35 | func ListOf(n Node, rep parquet.Repetition, fieldID int32) (*GroupNode, error) { | |
36 | if rep == parquet.Repetitions.Repeated || n.RepetitionType() == parquet.Repetitions.Repeated { | |
37 | return nil, xerrors.New("parquet: listof repetition and element repetition must not be repeated.") | |
38 | } | |
39 | listName := n.Name() | |
40 | ||
41 | switch n := n.(type) { | |
42 | case *PrimitiveNode: | |
43 | n.name = "element" | |
44 | case *GroupNode: | |
45 | n.name = "element" | |
46 | } | |
47 | ||
48 | list, err := NewGroupNode("list" /* name */, parquet.Repetitions.Repeated, FieldList{n}, -1 /* fieldID */) | |
49 | if err != nil { | |
50 | return nil, err | |
51 | } | |
52 | return NewGroupNodeLogical(listName, rep, FieldList{list}, ListLogicalType{}, fieldID) | |
53 | } | |
54 | ||
55 | // MapOf is a convenience helper function to create a properly structured | |
56 | // parquet map node setup according to the Parquet Spec. | |
57 | // | |
58 | // <map-repetition> group <name> (MAP) { | |
59 | // repeated group key_value { | |
60 | // required <key-type> key; | |
61 | // <value-repetition> <value-type> value; | |
62 | // } | |
63 | // } | |
64 | // | |
65 | // key node will be renamed to "key", value node if not nil will be renamed to "value" | |
66 | // | |
67 | // <map-repetition> must be only optional or required. panics if repeated is passed. | |
68 | // | |
69 | // the key node *must* be required repetition. panics if optional or repeated | |
70 | // | |
71 | // value node can be nil (omitted) or have a repetition of required or optional *only*. | |
72 | // panics if value node is not nil and has a repetition of repeated. | |
73 | func MapOf(name string, key Node, value Node, mapRep parquet.Repetition, fieldID int32) (*GroupNode, error) { | |
74 | if mapRep == parquet.Repetitions.Repeated { | |
75 | return nil, xerrors.New("parquet: map repetition cannot be Repeated") | |
76 | } | |
77 | if key.RepetitionType() != parquet.Repetitions.Required { | |
78 | return nil, xerrors.New("parquet: map key repetition must be Required") | |
79 | } | |
80 | if value != nil { | |
81 | if value.RepetitionType() == parquet.Repetitions.Repeated { | |
82 | return nil, xerrors.New("parquet: map value cannot have repetition Repeated") | |
83 | } | |
84 | switch value := value.(type) { | |
85 | case *PrimitiveNode: | |
86 | value.name = "value" | |
87 | case *GroupNode: | |
88 | value.name = "value" | |
89 | } | |
90 | } | |
91 | ||
92 | switch key := key.(type) { | |
93 | case *PrimitiveNode: | |
94 | key.name = "key" | |
95 | case *GroupNode: | |
96 | key.name = "key" | |
97 | } | |
98 | ||
99 | keyval := FieldList{key} | |
100 | if value != nil { | |
101 | keyval = append(keyval, value) | |
102 | } | |
103 | ||
104 | kvNode, err := NewGroupNode("key_value" /* name */, parquet.Repetitions.Repeated, keyval, -1 /* fieldID */) | |
105 | if err != nil { | |
106 | return nil, err | |
107 | } | |
108 | return NewGroupNodeLogical(name, mapRep, FieldList{kvNode}, MapLogicalType{}, fieldID) | |
109 | } |