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cae7420b DB |
1 | /** @file\r |
2 | Hash table operations.\r | |
b9ec9330 | 3 | \r |
e76bc43e | 4 | Copyright (c) 2005 - 2015, Intel Corporation. All rights reserved.<BR>\r |
6163cc98 | 5 | This program and the accompanying materials are licensed and made available\r |
b9ec9330 QH |
6 | under the terms and conditions of the BSD License which accompanies this\r |
7 | distribution. The full text of the license may be found at\r | |
8 | http://opensource.org/licenses/bsd-license.php\r | |
9 | \r | |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
12 | \r | |
cae7420b | 13 | **/\r |
b9ec9330 | 14 | \r |
cae7420b | 15 | #include "Fat.h"\r |
b9ec9330 | 16 | \r |
cae7420b | 17 | /**\r |
b9ec9330 | 18 | \r |
cae7420b | 19 | Get hash value for long name.\r |
b9ec9330 | 20 | \r |
cae7420b | 21 | @param LongNameString - The long name string to be hashed.\r |
b9ec9330 | 22 | \r |
cae7420b | 23 | @return HashValue.\r |
b9ec9330 | 24 | \r |
cae7420b | 25 | **/\r |
b9ec9330 QH |
26 | STATIC\r |
27 | UINT32\r | |
28 | FatHashLongName (\r | |
29 | IN CHAR16 *LongNameString\r | |
30 | )\r | |
b9ec9330 QH |
31 | {\r |
32 | UINT32 HashValue;\r | |
33 | CHAR16 UpCasedLongFileName[EFI_PATH_STRING_LENGTH];\r | |
e76bc43e HW |
34 | StrnCpyS (\r |
35 | UpCasedLongFileName,\r | |
0cdc10bd | 36 | ARRAY_SIZE (UpCasedLongFileName),\r |
e76bc43e | 37 | LongNameString,\r |
0cdc10bd | 38 | ARRAY_SIZE (UpCasedLongFileName) - 1\r |
e76bc43e | 39 | );\r |
b9ec9330 QH |
40 | FatStrUpr (UpCasedLongFileName);\r |
41 | gBS->CalculateCrc32 (UpCasedLongFileName, StrSize (UpCasedLongFileName), &HashValue);\r | |
42 | return (HashValue & HASH_TABLE_MASK);\r | |
43 | }\r | |
44 | \r | |
cae7420b | 45 | /**\r |
b9ec9330 QH |
46 | \r |
47 | Get hash value for short name.\r | |
48 | \r | |
cae7420b | 49 | @param ShortNameString - The short name string to be hashed.\r |
b9ec9330 | 50 | \r |
cae7420b | 51 | @return HashValue\r |
b9ec9330 | 52 | \r |
cae7420b DB |
53 | **/\r |
54 | STATIC\r | |
55 | UINT32\r | |
56 | FatHashShortName (\r | |
57 | IN CHAR8 *ShortNameString\r | |
58 | )\r | |
b9ec9330 QH |
59 | {\r |
60 | UINT32 HashValue;\r | |
61 | gBS->CalculateCrc32 (ShortNameString, FAT_NAME_LEN, &HashValue);\r | |
62 | return (HashValue & HASH_TABLE_MASK);\r | |
63 | }\r | |
64 | \r | |
cae7420b | 65 | /**\r |
b9ec9330 QH |
66 | \r |
67 | Search the long name hash table for the directory entry.\r | |
68 | \r | |
cae7420b DB |
69 | @param ODir - The directory to be searched.\r |
70 | @param LongNameString - The long name string to search.\r | |
b9ec9330 | 71 | \r |
cae7420b | 72 | @return The previous long name hash node of the directory entry.\r |
b9ec9330 | 73 | \r |
cae7420b DB |
74 | **/\r |
75 | FAT_DIRENT **\r | |
76 | FatLongNameHashSearch (\r | |
77 | IN FAT_ODIR *ODir,\r | |
78 | IN CHAR16 *LongNameString\r | |
79 | )\r | |
b9ec9330 QH |
80 | {\r |
81 | FAT_DIRENT **PreviousHashNode;\r | |
82 | for (PreviousHashNode = &ODir->LongNameHashTable[FatHashLongName (LongNameString)];\r | |
83 | *PreviousHashNode != NULL;\r | |
84 | PreviousHashNode = &(*PreviousHashNode)->LongNameForwardLink\r | |
85 | ) {\r | |
86 | if (FatStriCmp (LongNameString, (*PreviousHashNode)->FileString) == 0) {\r | |
87 | break;\r | |
88 | }\r | |
89 | }\r | |
90 | \r | |
91 | return PreviousHashNode;\r | |
92 | }\r | |
93 | \r | |
cae7420b | 94 | /**\r |
b9ec9330 QH |
95 | \r |
96 | Search the short name hash table for the directory entry.\r | |
97 | \r | |
cae7420b DB |
98 | @param ODir - The directory to be searched.\r |
99 | @param ShortNameString - The short name string to search.\r | |
b9ec9330 | 100 | \r |
cae7420b | 101 | @return The previous short name hash node of the directory entry.\r |
b9ec9330 | 102 | \r |
cae7420b DB |
103 | **/\r |
104 | FAT_DIRENT **\r | |
105 | FatShortNameHashSearch (\r | |
106 | IN FAT_ODIR *ODir,\r | |
107 | IN CHAR8 *ShortNameString\r | |
108 | )\r | |
b9ec9330 QH |
109 | {\r |
110 | FAT_DIRENT **PreviousHashNode;\r | |
111 | for (PreviousHashNode = &ODir->ShortNameHashTable[FatHashShortName (ShortNameString)];\r | |
112 | *PreviousHashNode != NULL;\r | |
113 | PreviousHashNode = &(*PreviousHashNode)->ShortNameForwardLink\r | |
114 | ) {\r | |
115 | if (CompareMem (ShortNameString, (*PreviousHashNode)->Entry.FileName, FAT_NAME_LEN) == 0) {\r | |
116 | break;\r | |
117 | }\r | |
118 | }\r | |
119 | \r | |
120 | return PreviousHashNode;\r | |
121 | }\r | |
122 | \r | |
cae7420b DB |
123 | /**\r |
124 | \r | |
125 | Insert directory entry to hash table.\r | |
126 | \r | |
127 | @param ODir - The parent directory.\r | |
128 | @param DirEnt - The directory entry node.\r | |
129 | \r | |
130 | **/\r | |
b9ec9330 QH |
131 | VOID\r |
132 | FatInsertToHashTable (\r | |
133 | IN FAT_ODIR *ODir,\r | |
134 | IN FAT_DIRENT *DirEnt\r | |
135 | )\r | |
b9ec9330 QH |
136 | {\r |
137 | FAT_DIRENT **HashTable;\r | |
138 | UINT32 HashTableIndex;\r | |
139 | \r | |
140 | //\r | |
141 | // Insert hash table index for short name\r | |
142 | //\r | |
143 | HashTableIndex = FatHashShortName (DirEnt->Entry.FileName);\r | |
144 | HashTable = ODir->ShortNameHashTable;\r | |
145 | DirEnt->ShortNameForwardLink = HashTable[HashTableIndex];\r | |
146 | HashTable[HashTableIndex] = DirEnt;\r | |
147 | //\r | |
148 | // Insert hash table index for long name\r | |
149 | //\r | |
150 | HashTableIndex = FatHashLongName (DirEnt->FileString);\r | |
151 | HashTable = ODir->LongNameHashTable;\r | |
152 | DirEnt->LongNameForwardLink = HashTable[HashTableIndex];\r | |
153 | HashTable[HashTableIndex] = DirEnt;\r | |
154 | }\r | |
155 | \r | |
cae7420b DB |
156 | /**\r |
157 | \r | |
158 | Delete directory entry from hash table.\r | |
159 | \r | |
160 | @param ODir - The parent directory.\r | |
161 | @param DirEnt - The directory entry node.\r | |
162 | \r | |
163 | **/\r | |
b9ec9330 QH |
164 | VOID\r |
165 | FatDeleteFromHashTable (\r | |
166 | IN FAT_ODIR *ODir,\r | |
167 | IN FAT_DIRENT *DirEnt\r | |
168 | )\r | |
b9ec9330 QH |
169 | {\r |
170 | *FatShortNameHashSearch (ODir, DirEnt->Entry.FileName) = DirEnt->ShortNameForwardLink;\r | |
171 | *FatLongNameHashSearch (ODir, DirEnt->FileString) = DirEnt->LongNameForwardLink;\r | |
172 | }\r |