diff options
Diffstat (limited to '')
| -rw-r--r-- | src/stable/myriad.h | 426 |
1 files changed, 213 insertions, 213 deletions
diff --git a/src/stable/myriad.h b/src/stable/myriad.h index 6b1db41..4bfd88e 100644 --- a/src/stable/myriad.h +++ b/src/stable/myriad.h | |||
| @@ -18,219 +18,219 @@ | |||
| 18 | 18 | ||
| 19 | namespace Bu | 19 | namespace Bu |
| 20 | { | 20 | { |
| 21 | class Stream; | 21 | class Stream; |
| 22 | class MyriadStream; | 22 | class MyriadStream; |
| 23 | 23 | ||
| 24 | subExceptionDeclBegin( MyriadException ) | 24 | subExceptionDeclBegin( MyriadException ) |
| 25 | enum | 25 | enum |
| 26 | { | 26 | { |
| 27 | emptyStream, | 27 | emptyStream, |
| 28 | invalidFormat, | 28 | invalidFormat, |
| 29 | badVersion, | 29 | badVersion, |
| 30 | invalidWordSize, | 30 | invalidWordSize, |
| 31 | noSuchStream, | 31 | noSuchStream, |
| 32 | streamExists, | 32 | streamExists, |
| 33 | invalidStreamId, | 33 | invalidStreamId, |
| 34 | protectedStream | 34 | protectedStream |
| 35 | }; | 35 | }; |
| 36 | subExceptionDeclEnd(); | 36 | subExceptionDeclEnd(); |
| 37 | 37 | ||
| 38 | /** | 38 | /** |
| 39 | * Myriad block-allocated stream multiplexing system. This is a system for | 39 | * Myriad block-allocated stream multiplexing system. This is a system for |
| 40 | * creating streams that contain other streams in a flexible and lightweight | 40 | * creating streams that contain other streams in a flexible and lightweight |
| 41 | * manner. Basically, you can create a file (or any other stream) that can | 41 | * manner. Basically, you can create a file (or any other stream) that can |
| 42 | * store any number of flexible, growing streams. The streams within the | 42 | * store any number of flexible, growing streams. The streams within the |
| 43 | * Myriad stream are automatically numbered, not named. This works more | 43 | * Myriad stream are automatically numbered, not named. This works more |
| 44 | * or less like a filesystem, but without the extra layer for managing | 44 | * or less like a filesystem, but without the extra layer for managing |
| 45 | * file and directory links. This would actually be very easy to add | 45 | * file and directory links. This would actually be very easy to add |
| 46 | * on top of Myriad, but is not required. | 46 | * on top of Myriad, but is not required. |
| 47 | * | 47 | * |
| 48 | * Header format is as follows: | 48 | * Header format is as follows: |
| 49 | * | 49 | * |
| 50 | * MMMMvBssssSSSS* | 50 | * MMMMvBssssSSSS* |
| 51 | * M = Magic number (0AD3FA84) | 51 | * M = Magic number (0AD3FA84) |
| 52 | * v = version number | 52 | * v = version number |
| 53 | * B = Bits per int | 53 | * B = Bits per int |
| 54 | * s = Blocksize in bytes | 54 | * s = Blocksize in bytes |
| 55 | * S = Number of Streams | 55 | * S = Number of Streams |
| 56 | * | 56 | * |
| 57 | * The * represents the Stream headers, one per stream, as follows: | 57 | * The * represents the Stream headers, one per stream, as follows: |
| 58 | * IIIIssss$ | 58 | * IIIIssss$ |
| 59 | * I = Id number of the stream | 59 | * I = Id number of the stream |
| 60 | * s = size of stream in bytes | 60 | * s = size of stream in bytes |
| 61 | * | 61 | * |
| 62 | * The $ represents the Block headers, one per used block, as follows: | 62 | * The $ represents the Block headers, one per used block, as follows: |
| 63 | * IIII | 63 | * IIII |
| 64 | * I = Index of the block | 64 | * I = Index of the block |
| 65 | * | 65 | * |
| 66 | * The stream/block data is interleaved in the header, so all blocks stored | 66 | * The stream/block data is interleaved in the header, so all blocks stored |
| 67 | * with one stream are together. The block headers are in order, and the | 67 | * with one stream are together. The block headers are in order, and the |
| 68 | * data in them is required to be "solid" you cannot fill partial blocks | 68 | * data in them is required to be "solid" you cannot fill partial blocks |
| 69 | * mid-way through a stream. | 69 | * mid-way through a stream. |
| 70 | * | 70 | * |
| 71 | * The initial block starts with the nids header, and is both the zero block | 71 | * The initial block starts with the nids header, and is both the zero block |
| 72 | * and the zero stream. For now, the minimum block size is the size needed | 72 | * and the zero stream. For now, the minimum block size is the size needed |
| 73 | * to store the base header, the zero stream header, and the first two | 73 | * to store the base header, the zero stream header, and the first two |
| 74 | * blocks of the zero stream, so 30 bytes. Since it's reccomended to use | 74 | * blocks of the zero stream, so 30 bytes. Since it's reccomended to use |
| 75 | * a size that will fit evenly into filesystem blocks, then a size of 32 is | 75 | * a size that will fit evenly into filesystem blocks, then a size of 32 is |
| 76 | * probably the smallest reccomended size because all powers of two equal | 76 | * probably the smallest reccomended size because all powers of two equal |
| 77 | * to or greater than 32 are evenly divisible by 32. | 77 | * to or greater than 32 are evenly divisible by 32. |
| 78 | * | 78 | * |
| 79 | * I have had a thought that if the block size were smaller than 42 bytes | 79 | * I have had a thought that if the block size were smaller than 42 bytes |
| 80 | * the header would consume the first N blocks where N * block size is | 80 | * the header would consume the first N blocks where N * block size is |
| 81 | * enough space to house the initial header, the first stream header, and | 81 | * enough space to house the initial header, the first stream header, and |
| 82 | * the first N block headers. This, of course, causes you to hit an | 82 | * the first N block headers. This, of course, causes you to hit an |
| 83 | * infinite header if the block size is small enough. | 83 | * infinite header if the block size is small enough. |
| 84 | */ | 84 | */ |
| 85 | class Myriad | 85 | class Myriad |
| 86 | { | 86 | { |
| 87 | friend class MyriadStream; | 87 | friend class MyriadStream; |
| 88 | public: | 88 | public: |
| 89 | /** | 89 | /** |
| 90 | * Create a Myriad object that uses the given stream to store data. | 90 | * Create a Myriad object that uses the given stream to store data. |
| 91 | * This stream must be random access. The block size and preallocate | 91 | * This stream must be random access. The block size and preallocate |
| 92 | * values passed in are values that will be used if the given stream | 92 | * values passed in are values that will be used if the given stream |
| 93 | * is empty. In that case the stream will be "formatted" for myriad | 93 | * is empty. In that case the stream will be "formatted" for myriad |
| 94 | * with the specified block size. If there is already a viable Myriad | 94 | * with the specified block size. If there is already a viable Myriad |
| 95 | * format present in the stream, then the blocksize and preallocate | 95 | * format present in the stream, then the blocksize and preallocate |
| 96 | * values will be ignored and the values from the stream will be used | 96 | * values will be ignored and the values from the stream will be used |
| 97 | * instead. If the stream doesn't appear to be Myriad formatted an | 97 | * instead. If the stream doesn't appear to be Myriad formatted an |
| 98 | * exception will be thrown. | 98 | * exception will be thrown. |
| 99 | */ | 99 | */ |
| 100 | Myriad( Bu::Stream &sStore, int iBlockSize=512, int iPreallocate=8 ); | 100 | Myriad( Bu::Stream &sStore, int iBlockSize=512, int iPreallocate=8 ); |
| 101 | virtual ~Myriad(); | 101 | virtual ~Myriad(); |
| 102 | 102 | ||
| 103 | /** | 103 | /** |
| 104 | * Destroy whatever data may be in the base stream and create a new | 104 | * Destroy whatever data may be in the base stream and create a new |
| 105 | * Myriad system there with the given blocksize. Use this with care, | 105 | * Myriad system there with the given blocksize. Use this with care, |
| 106 | * it will destroy anything that was already in the stream, and | 106 | * it will destroy anything that was already in the stream, and |
| 107 | * generally, should not ever have to be used. | 107 | * generally, should not ever have to be used. |
| 108 | */ | 108 | */ |
| 109 | void initialize( int iBlockSize, int iPreAllocate=1 ); | 109 | void initialize( int iBlockSize, int iPreAllocate=1 ); |
| 110 | 110 | ||
| 111 | /** | 111 | /** |
| 112 | * Create a new stream within the Myriad system. The ID of the new | 112 | * Create a new stream within the Myriad system. The ID of the new |
| 113 | * stream is returned. | 113 | * stream is returned. |
| 114 | */ | 114 | */ |
| 115 | int createStream( int iPreAllocate=1 ); | 115 | int createStream( int iPreAllocate=1 ); |
| 116 | 116 | ||
| 117 | /** | 117 | /** |
| 118 | * Create a new stream within the Myriad system with a given id. The | 118 | * Create a new stream within the Myriad system with a given id. The |
| 119 | * id that you provide will be the new id of the stream unless it's | 119 | * id that you provide will be the new id of the stream unless it's |
| 120 | * already used, in which case an error is thrown. This is primarilly | 120 | * already used, in which case an error is thrown. This is primarilly |
| 121 | * useful when copying an old Myriad file into a new one. | 121 | * useful when copying an old Myriad file into a new one. |
| 122 | */ | 122 | */ |
| 123 | int createStreamWithId( int iId, int iPreAllocate=1 ); | 123 | int createStreamWithId( int iId, int iPreAllocate=1 ); |
| 124 | 124 | ||
| 125 | /** | 125 | /** |
| 126 | * Delete a stream that's already within the Myriad. | 126 | * Delete a stream that's already within the Myriad. |
| 127 | */ | 127 | */ |
| 128 | void deleteStream( int iId ); | 128 | void deleteStream( int iId ); |
| 129 | 129 | ||
| 130 | /** | 130 | /** |
| 131 | * Return a new Stream object assosiated with the given stream ID. | 131 | * Return a new Stream object assosiated with the given stream ID. |
| 132 | */ | 132 | */ |
| 133 | MyriadStream openStream( int iId ); | 133 | MyriadStream openStream( int iId ); |
| 134 | 134 | ||
| 135 | Bu::Array<int> getStreamIds(); | 135 | Bu::Array<int> getStreamIds(); |
| 136 | int getStreamSize( int iId ); | 136 | int getStreamSize( int iId ); |
| 137 | bool hasStream( int iId ); | 137 | bool hasStream( int iId ); |
| 138 | 138 | ||
| 139 | int getNumStreams(); | 139 | int getNumStreams(); |
| 140 | int getBlockSize(); | 140 | int getBlockSize(); |
| 141 | int getNumBlocks(); | 141 | int getNumBlocks(); |
| 142 | int getNumUsedBlocks(); | 142 | int getNumUsedBlocks(); |
| 143 | Bu::size getTotalUsedBytes(); | 143 | Bu::size getTotalUsedBytes(); |
| 144 | Bu::size getTotalUnusedBytes(); | 144 | Bu::size getTotalUnusedBytes(); |
| 145 | Bu::size getTotalUnusedBytes( int iFakeBlockSize ); | 145 | Bu::size getTotalUnusedBytes( int iFakeBlockSize ); |
| 146 | 146 | ||
| 147 | /** | 147 | /** |
| 148 | * Syncronize the header data, etc. with the storage stream. It's not | 148 | * Syncronize the header data, etc. with the storage stream. It's not |
| 149 | * a bad idea to call this periodically. | 149 | * a bad idea to call this periodically. |
| 150 | */ | 150 | */ |
| 151 | void sync(); | 151 | void sync(); |
| 152 | 152 | ||
| 153 | /** | 153 | /** |
| 154 | * Read the first few bytes from the given stream and return true/false | 154 | * Read the first few bytes from the given stream and return true/false |
| 155 | * depending on weather or not it's a Myriad stream. This will throw | 155 | * depending on weather or not it's a Myriad stream. This will throw |
| 156 | * an exception if the stream is empty, or is not random access. | 156 | * an exception if the stream is empty, or is not random access. |
| 157 | */ | 157 | */ |
| 158 | static bool isMyriad( Bu::Stream &sStore, uint8_t &uVer ); | 158 | static bool isMyriad( Bu::Stream &sStore, uint8_t &uVer ); |
| 159 | 159 | ||
| 160 | /** | 160 | /** |
| 161 | * Read the first few bytes from the given stream and return true/false | 161 | * Read the first few bytes from the given stream and return true/false |
| 162 | * depending on weather or not it's a Myriad stream. This will throw | 162 | * depending on weather or not it's a Myriad stream. This will throw |
| 163 | * an exception if the stream is empty, or is not random access. | 163 | * an exception if the stream is empty, or is not random access. |
| 164 | */ | 164 | */ |
| 165 | static bool isMyriad( Bu::Stream &sStore ); | 165 | static bool isMyriad( Bu::Stream &sStore ); |
| 166 | 166 | ||
| 167 | const Bu::BitString getBlocksUsed() const; | 167 | const Bu::BitString getBlocksUsed() const; |
| 168 | 168 | ||
| 169 | private: | 169 | private: |
| 170 | /** | 170 | /** |
| 171 | * Initialize this object based on the data already in the assosiated | 171 | * Initialize this object based on the data already in the assosiated |
| 172 | * stream. This will be called automatically for you if you forget, | 172 | * stream. This will be called automatically for you if you forget, |
| 173 | * but if you want to pre-initialize for some reason, just call this | 173 | * but if you want to pre-initialize for some reason, just call this |
| 174 | * once before you actually start doing anything with your Myriad. | 174 | * once before you actually start doing anything with your Myriad. |
| 175 | */ | 175 | */ |
| 176 | void initialize(); | 176 | void initialize(); |
| 177 | 177 | ||
| 178 | enum | 178 | enum |
| 179 | { | 179 | { |
| 180 | blockUnused = 0xFFFFFFFFUL | 180 | blockUnused = 0xFFFFFFFFUL |
| 181 | }; | 181 | }; |
| 182 | 182 | ||
| 183 | typedef Bu::Array<int> BlockArray; | 183 | typedef Bu::Array<int> BlockArray; |
| 184 | class Stream | 184 | class Stream |
| 185 | { | 185 | { |
| 186 | public: | 186 | public: |
| 187 | int iId; | 187 | int iId; |
| 188 | int iSize; | 188 | int iSize; |
| 189 | BlockArray aBlocks; | 189 | BlockArray aBlocks; |
| 190 | }; | 190 | }; |
| 191 | typedef Bu::Array<Stream *> StreamArray; | 191 | typedef Bu::Array<Stream *> StreamArray; |
| 192 | 192 | ||
| 193 | class Block | 193 | class Block |
| 194 | { | 194 | { |
| 195 | public: | 195 | public: |
| 196 | char *pData; | 196 | char *pData; |
| 197 | bool bChanged; | 197 | bool bChanged; |
| 198 | int iBlockIndex; | 198 | int iBlockIndex; |
| 199 | }; | 199 | }; |
| 200 | 200 | ||
| 201 | void updateHeader(); | 201 | void updateHeader(); |
| 202 | int findEmptyBlock(); | 202 | int findEmptyBlock(); |
| 203 | 203 | ||
| 204 | /** | 204 | /** |
| 205 | *@todo Change this to use a binary search, it's nicer. | 205 | *@todo Change this to use a binary search, it's nicer. |
| 206 | */ | 206 | */ |
| 207 | Stream *findStream( int iId ); | 207 | Stream *findStream( int iId ); |
| 208 | 208 | ||
| 209 | Block *getBlock( int iBlock ); | 209 | Block *getBlock( int iBlock ); |
| 210 | void releaseBlock( Block *pBlock ); | 210 | void releaseBlock( Block *pBlock ); |
| 211 | void syncBlock( Block *pBlock ); | 211 | void syncBlock( Block *pBlock ); |
| 212 | 212 | ||
| 213 | int streamAddBlock( Stream *pStream ); | 213 | int streamAddBlock( Stream *pStream ); |
| 214 | void setStreamSize( Stream *pStream, long iSize ); | 214 | void setStreamSize( Stream *pStream, long iSize ); |
| 215 | 215 | ||
| 216 | void headerChanged(); | 216 | void headerChanged(); |
| 217 | 217 | ||
| 218 | private: | 218 | private: |
| 219 | Bu::Stream &sStore; | 219 | Bu::Stream &sStore; |
| 220 | int iBlockSize; | 220 | int iBlockSize; |
| 221 | int iBlocks; | 221 | int iBlocks; |
| 222 | int iUsed; | 222 | int iUsed; |
| 223 | typedef Bu::List<int> IndexList; | 223 | typedef Bu::List<int> IndexList; |
| 224 | IndexList lFreeBlocks; | 224 | IndexList lFreeBlocks; |
| 225 | // Bu::BitString bsBlockUsed; | 225 | // Bu::BitString bsBlockUsed; |
| 226 | StreamArray aStreams; | 226 | StreamArray aStreams; |
| 227 | typedef Bu::Hash<int, Block *> BlockHash; | 227 | typedef Bu::Hash<int, Block *> BlockHash; |
| 228 | BlockHash hActiveBlocks; | 228 | BlockHash hActiveBlocks; |
| 229 | bool bHeaderChanged; | 229 | bool bHeaderChanged; |
| 230 | 230 | ||
| 231 | Bu::Mutex mHeader; | 231 | Bu::Mutex mHeader; |
| 232 | Bu::Mutex mActiveBlocks; | 232 | Bu::Mutex mActiveBlocks; |
| 233 | }; | 233 | }; |
| 234 | }; | 234 | }; |
| 235 | 235 | ||
| 236 | #endif | 236 | #endif |
