* Sync up to trunk head (r65353).
[reactos.git] / drivers / storage / classpnp / dictlib.c
1 /*++
2
3 Copyright (C) Microsoft Corporation, 1990 - 1999
4
5 Module Name:
6
7 dictlib.c
8
9 Abstract:
10
11 Support library for maintaining a dictionary list (list of objects
12 referenced by a key value).
13
14 Environment:
15
16 kernel mode only
17
18 Notes:
19
20 This module generates a static library
21
22 Revision History:
23
24 --*/
25
26 #include "classp.h"
27
28 #define DICTIONARY_SIGNATURE 'dsig'
29
30 typedef struct _DICTIONARY_HEADER {
31 struct _DICTIONARY_HEADER* Next;
32 ULONGLONG Key;
33 UCHAR Data[0];
34 } DICTIONARY_HEADER, *PDICTIONARY_HEADER;
35
36
37 VOID
38 NTAPI
39 InitializeDictionary(
40 IN PDICTIONARY Dictionary
41 )
42 {
43 RtlZeroMemory(Dictionary, sizeof(DICTIONARY));
44 Dictionary->Signature = DICTIONARY_SIGNATURE;
45 KeInitializeSpinLock(&Dictionary->SpinLock);
46 return;
47 }
48
49 BOOLEAN
50 NTAPI
51 TestDictionarySignature(
52 IN PDICTIONARY Dictionary
53 )
54 {
55 return Dictionary->Signature == DICTIONARY_SIGNATURE;
56 }
57
58 NTSTATUS
59 NTAPI
60 AllocateDictionaryEntry(
61 IN PDICTIONARY Dictionary,
62 IN ULONGLONG Key,
63 IN ULONG Size,
64 IN ULONG Tag,
65 OUT PVOID *Entry
66 )
67 {
68 PDICTIONARY_HEADER header;
69 KIRQL oldIrql;
70 PDICTIONARY_HEADER *entry;
71
72 NTSTATUS status = STATUS_SUCCESS;
73
74 *Entry = NULL;
75
76 header = ExAllocatePoolWithTag(NonPagedPool,
77 Size + sizeof(DICTIONARY_HEADER),
78 Tag);
79
80 if(header == NULL) {
81 return STATUS_INSUFFICIENT_RESOURCES;
82 }
83
84 RtlZeroMemory(header, sizeof(DICTIONARY_HEADER) + Size);
85 header->Key = Key;
86
87 //
88 // Find the correct location for this entry in the dictionary.
89 //
90
91 KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
92
93 TRY {
94
95 entry = &(Dictionary->List);
96
97 while(*entry != NULL) {
98 if((*entry)->Key == Key) {
99
100 //
101 // Dictionary must have unique keys.
102 //
103
104 status = STATUS_OBJECT_NAME_COLLISION;
105 LEAVE;
106
107 } else if ((*entry)->Key < Key) {
108
109 //
110 // We will go ahead and insert the key in here.
111 //
112 break;
113 } else {
114 entry = &((*entry)->Next);
115 }
116 }
117
118 //
119 // If we make it here then we will go ahead and do the insertion.
120 //
121
122 header->Next = *entry;
123 *entry = header;
124
125 } FINALLY {
126 KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
127
128 if(!NT_SUCCESS(status)) {
129 ExFreePool(header);
130 } else {
131 *Entry = (PVOID) header->Data;
132 }
133 }
134 return status;
135 }
136
137 PVOID
138 NTAPI
139 GetDictionaryEntry(
140 IN PDICTIONARY Dictionary,
141 IN ULONGLONG Key
142 )
143 {
144 PDICTIONARY_HEADER entry;
145 PVOID data;
146 KIRQL oldIrql;
147
148
149 data = NULL;
150
151 KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
152
153 entry = Dictionary->List;
154 while (entry != NULL) {
155
156 if (entry->Key == Key) {
157 data = entry->Data;
158 break;
159 } else {
160 entry = entry->Next;
161 }
162 }
163
164 KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
165
166 return data;
167 }
168
169 VOID
170 NTAPI
171 FreeDictionaryEntry(
172 IN PDICTIONARY Dictionary,
173 IN PVOID Entry
174 )
175 {
176 PDICTIONARY_HEADER header;
177 PDICTIONARY_HEADER *entry;
178 KIRQL oldIrql;
179 BOOLEAN found;
180
181 found = FALSE;
182 header = CONTAINING_RECORD(Entry, DICTIONARY_HEADER, Data);
183
184 KeAcquireSpinLock(&(Dictionary->SpinLock), &oldIrql);
185
186 entry = &(Dictionary->List);
187 while(*entry != NULL) {
188
189 if(*entry == header) {
190 *entry = header->Next;
191 found = TRUE;
192 break;
193 } else {
194 entry = &(*entry)->Next;
195 }
196 }
197
198 KeReleaseSpinLock(&(Dictionary->SpinLock), oldIrql);
199
200 //
201 // calling this w/an invalid pointer invalidates the dictionary system,
202 // so ASSERT() that we never try to Free something not in the list
203 //
204
205 ASSERT(found);
206 if (found) {
207 ExFreePool(header);
208 }
209
210 return;
211
212 }