diff options
author | Jake Champlin <jake.champlin.27@gmail.com> | 2017-06-06 12:40:07 -0400 |
---|---|---|
committer | Jake Champlin <jake.champlin.27@gmail.com> | 2017-06-06 12:40:07 -0400 |
commit | bae9f6d2fd5eb5bc80929bd393932b23f14d7c93 (patch) | |
tree | ca9ab12a7d78b1fc27a8f734729081357ce6d252 /vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go | |
parent | 254c495b6bebab3fb72a243c4bce858d79e6ee99 (diff) | |
download | terraform-provider-statuscake-bae9f6d2fd5eb5bc80929bd393932b23f14d7c93.tar.gz terraform-provider-statuscake-bae9f6d2fd5eb5bc80929bd393932b23f14d7c93.tar.zst terraform-provider-statuscake-bae9f6d2fd5eb5bc80929bd393932b23f14d7c93.zip |
Initial transfer of provider code
Diffstat (limited to 'vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go')
-rw-r--r-- | vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go b/vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go new file mode 100644 index 0000000..4223e92 --- /dev/null +++ b/vendor/github.com/hashicorp/terraform/helper/shadow/compared_value.go | |||
@@ -0,0 +1,128 @@ | |||
1 | package shadow | ||
2 | |||
3 | import ( | ||
4 | "sync" | ||
5 | ) | ||
6 | |||
7 | // ComparedValue is a struct that finds a value by comparing some key | ||
8 | // to the list of stored values. This is useful when there is no easy | ||
9 | // uniquely identifying key that works in a map (for that, use KeyedValue). | ||
10 | // | ||
11 | // ComparedValue is very expensive, relative to other Value types. Try to | ||
12 | // limit the number of values stored in a ComparedValue by potentially | ||
13 | // nesting it within a KeyedValue (a keyed value points to a compared value, | ||
14 | // for example). | ||
15 | type ComparedValue struct { | ||
16 | // Func is a function that is given the lookup key and a single | ||
17 | // stored value. If it matches, it returns true. | ||
18 | Func func(k, v interface{}) bool | ||
19 | |||
20 | lock sync.Mutex | ||
21 | once sync.Once | ||
22 | closed bool | ||
23 | values []interface{} | ||
24 | waiters map[interface{}]*Value | ||
25 | } | ||
26 | |||
27 | // Close closes the value. This can never fail. For a definition of | ||
28 | // "close" see the ErrClosed docs. | ||
29 | func (w *ComparedValue) Close() error { | ||
30 | w.lock.Lock() | ||
31 | defer w.lock.Unlock() | ||
32 | |||
33 | // Set closed to true always | ||
34 | w.closed = true | ||
35 | |||
36 | // For all waiters, complete with ErrClosed | ||
37 | for k, val := range w.waiters { | ||
38 | val.SetValue(ErrClosed) | ||
39 | delete(w.waiters, k) | ||
40 | } | ||
41 | |||
42 | return nil | ||
43 | } | ||
44 | |||
45 | // Value returns the value that was set for the given key, or blocks | ||
46 | // until one is available. | ||
47 | func (w *ComparedValue) Value(k interface{}) interface{} { | ||
48 | v, val := w.valueWaiter(k) | ||
49 | if val == nil { | ||
50 | return v | ||
51 | } | ||
52 | |||
53 | return val.Value() | ||
54 | } | ||
55 | |||
56 | // ValueOk gets the value for the given key, returning immediately if the | ||
57 | // value doesn't exist. The second return argument is true if the value exists. | ||
58 | func (w *ComparedValue) ValueOk(k interface{}) (interface{}, bool) { | ||
59 | v, val := w.valueWaiter(k) | ||
60 | return v, val == nil | ||
61 | } | ||
62 | |||
63 | func (w *ComparedValue) SetValue(v interface{}) { | ||
64 | w.lock.Lock() | ||
65 | defer w.lock.Unlock() | ||
66 | w.once.Do(w.init) | ||
67 | |||
68 | // Check if we already have this exact value (by simply comparing | ||
69 | // with == directly). If we do, then we don't insert it again. | ||
70 | found := false | ||
71 | for _, v2 := range w.values { | ||
72 | if v == v2 { | ||
73 | found = true | ||
74 | break | ||
75 | } | ||
76 | } | ||
77 | |||
78 | if !found { | ||
79 | // Set the value, always | ||
80 | w.values = append(w.values, v) | ||
81 | } | ||
82 | |||
83 | // Go through the waiters | ||
84 | for k, val := range w.waiters { | ||
85 | if w.Func(k, v) { | ||
86 | val.SetValue(v) | ||
87 | delete(w.waiters, k) | ||
88 | } | ||
89 | } | ||
90 | } | ||
91 | |||
92 | func (w *ComparedValue) valueWaiter(k interface{}) (interface{}, *Value) { | ||
93 | w.lock.Lock() | ||
94 | w.once.Do(w.init) | ||
95 | |||
96 | // Look for a pre-existing value | ||
97 | for _, v := range w.values { | ||
98 | if w.Func(k, v) { | ||
99 | w.lock.Unlock() | ||
100 | return v, nil | ||
101 | } | ||
102 | } | ||
103 | |||
104 | // If we're closed, return that | ||
105 | if w.closed { | ||
106 | w.lock.Unlock() | ||
107 | return ErrClosed, nil | ||
108 | } | ||
109 | |||
110 | // Pre-existing value doesn't exist, create a waiter | ||
111 | val := w.waiters[k] | ||
112 | if val == nil { | ||
113 | val = new(Value) | ||
114 | w.waiters[k] = val | ||
115 | } | ||
116 | w.lock.Unlock() | ||
117 | |||
118 | // Return the waiter | ||
119 | return nil, val | ||
120 | } | ||
121 | |||
122 | // Must be called with w.lock held. | ||
123 | func (w *ComparedValue) init() { | ||
124 | w.waiters = make(map[interface{}]*Value) | ||
125 | if w.Func == nil { | ||
126 | w.Func = func(k, v interface{}) bool { return k == v } | ||
127 | } | ||
128 | } | ||