1 files changed, 222 insertions, 0 deletions
diff --git a/src/unstable/myriad.h b/src/unstable/myriad.h
new file mode 100644
index 0000000..3382ab5
--- /dev/null
+++ b/src/unstable/myriad.h
@@ -0,0 +1,222 @@
+/*
+ * Copyright (C) 2007-2011 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+#ifndef BU_MYRIAD_H
+#define BU_MYRIAD_H
+#include <stdint.h>
+#include "bu/bitstring.h"
+#include "bu/exceptionbase.h"
+#include "bu/array.h"
+#include "bu/hash.h"
+namespace Bu
+{
+        class Stream;
+        class MyriadStream;
+        subExceptionDeclBegin( MyriadException )
+                enum
+                {
+                        emptyStream,
+                        invalidFormat,
+                        badVersion,
+                        invalidWordSize,
+                        noSuchStream,
+                        streamExists,
+                        invalidStreamId,
+                        protectedStream
+                };
+        subExceptionDeclEnd();
+        /**
+         * Myriad block-allocated stream multiplexing system.  This is a system for
+         * creating streams that contain other streams in a flexible and lightweight
+         * manner.  Basically, you can create a file (or any other stream) that can
+         * store any number of flexible, growing streams.  The streams within the
+         * Myriad stream are automatically numbered, not named.  This works more
+         * or less like a filesystem, but without the extra layer for managing
+         * file and directory links.  This would actually be very easy to add
+         * on top of Myriad, but is not required.
+         *
+         * Header format is as follows:
+         *
+         * MMMMvBssssSSSS*
+         * M = Magic number (0AD3FA84)
+         * v = version number
+         * B = Bits per int
+         * s = Blocksize in bytes
+         * S = Number of Streams
+         * 
+         * The * represents the Stream headers, one per stream, as follows:
+         * IIIIssss$
+         * I = Id number of the stream
+         * s = size of stream in bytes
+         *
+         * The $ represents the Block headers, one per used block, as  follows:
+         * IIII
+         * I = Index of the block
+         *
+         * The stream/block data is interleaved in the header, so all blocks stored
+         * with one stream are together.  The block headers are in order, and the
+         * data in them is required to be "solid" you cannot fill partial blocks
+         * mid-way through a stream.
+         *
+         * The initial block starts with the nids header, and is both the zero block
+         * and the zero stream.  For now, the minimum block size is the size needed
+         * to store the base header, the zero stream header, and the first two
+         * blocks of the zero stream, so 30 bytes.  Since it's reccomended to use
+         * a size that will fit evenly into filesystem blocks, then a size of 32 is
+         * probably the smallest reccomended size because all powers of two equal
+         * to or greater than 32 are evenly divisible by 32.
+         *
+         * I have had a thought that if the block size were smaller than 42 bytes
+         * the header would consume the first N blocks where N * block size is
+         * enough space to house the initial header, the first stream header, and
+         * the first N block headers.  This, of course, causes you to hit an
+         * infinite header if the block size is small enough.
+         */
+        class Myriad
+        {
+                friend class MyriadStream;
+        public:
+                /**
+                 * Create a Myriad object that uses the given stream to store data.
+                 * This stream must be random access.  The block size and preallocate
+                 * values passed in are values that will be used if the given stream
+                 * is empty.  In that case the stream will be "formatted" for myriad
+                 * with the specified block size.  If there is already a viable Myriad
+                 * format present in the stream, then the blocksize and preallocate
+                 * values will be ignored and the values from the stream will be used
+                 * instead.  If the stream doesn't appear to be Myriad formatted an
+                 * exception will be thrown.
+                 */
+                Myriad( Bu::Stream &sStore, int iBlockSize=512, int iPreallocate=8 );
+                virtual ~Myriad();
+                /**
+                 * Destroy whatever data may be in the base stream and create a new
+                 * Myriad system there with the given blocksize.  Use this with care,
+                 * it will destroy anything that was already in the stream, and
+                 * generally, should not ever have to be used.
+                 */
+                void initialize( int iBlockSize, int iPreAllocate=1 );
+                /**
+                 * Create a new stream within the Myriad system.  The ID of the new
+                 * stream is returned.
+                 */
+                int createStream( int iPreAllocate=1 );
+                /**
+                 * Create a new stream within the Myriad system with a given id.  The
+                 * id that you provide will be the new id of the stream unless it's
+                 * already used, in which case an error is thrown.  This is primarilly
+                 * useful when copying an old Myriad file into a new one.
+                 */
+                int createStreamWithId( int iId, int iPreAllocate=1 );
+                /**
+                 * Delete a stream that's already within the Myriad.
+                 */
+                void deleteStream( int iId );
+                /**
+                 * Return a new Stream object assosiated with the given stream ID.
+                 */
+                MyriadStream openStream( int iId );
+                Bu::Array<int> getStreamIds();
+                int getStreamSize( int iId );
+                bool hasStream( int iId );
+                int getNumStreams();
+                int getBlockSize();
+                int getNumBlocks();
+                int getNumUsedBlocks();
+                int getTotalUsedBytes();
+                int getTotalUnusedBytes();
+                int getTotalUnusedBytes( int iFakeBlockSize );
+                /**
+                 * Syncronize the header data, etc. with the storage stream.  It's not
+                 * a bad idea to call this periodically.
+                 */
+                void sync();
+                /**
+                 * Read the first few bytes from the given stream and return true/false
+                 * depending on weather or not it's a Myriad stream.  This will throw
+                 * an exception if the stream is empty, or is not random access.
+                 */
+                static bool isMyriad( Bu::Stream &sStore );
+                const Bu::BitString &getBlocksUsed() const;
+        private:
+                /**
+                 * Initialize this object based on the data already in the assosiated
+                 * stream.  This will be called automatically for you if you forget,
+                 * but if you want to pre-initialize for some reason, just call this
+                 * once before you actually start doing anything with your Myriad.
+                 */
+                void initialize();
+                enum
+                {
+                        blockUnused     =       0xFFFFFFFFUL
+                };
+                
+                typedef Bu::Array<int> BlockArray;
+                class Stream
+                {
+                public:
+                        int iId;
+                        int iSize;
+                        BlockArray aBlocks;
+                };
+                typedef Bu::Array<Stream *> StreamArray;
+                class Block
+                {
+                public:
+                        char *pData;
+                        bool bChanged;
+                        int iBlockIndex;
+                };
+                void updateHeader();
+                int findEmptyBlock();
+                /**
+                 *@todo Change this to use a binary search, it's nicer.
+                 */
+                Stream *findStream( int iId );
+                Block *getBlock( int iBlock );
+                void releaseBlock( Block *pBlock );
+                void syncBlock( Block *pBlock );
+                int streamAddBlock( Stream *pStream );
+                void setStreamSize( Stream *pStream, long iSize );
+                void headerChanged();
+        private:
+                Bu::Stream &sStore;
+                int iBlockSize;
+                int iBlocks;
+                int iUsed;
+                Bu::BitString bsBlockUsed;
+                StreamArray aStreams;
+                typedef Bu::Hash<int, Block *> BlockHash;
+                BlockHash hActiveBlocks;
+                bool bHeaderChanged;
+        };
+};
+#endif

diff --git a/src/unstable/myriad.h b/src/unstable/myriad.h new file mode 100644 index 0000000..3382ab5 --- /dev/null +++ b/src/unstable/myriad.h
@@ -0,0 +1,222 @@
	1	/*
	2	* Copyright (C) 2007-2011 Xagasoft, All rights reserved.
	3	*
	4	* This file is part of the libbu++ library and is released under the
	5	* terms of the license contained in the file LICENSE.
	6	*/
	7
	8	#ifndef BU_MYRIAD_H
	9	#define BU_MYRIAD_H
	10
	11	#include <stdint.h>
	12	#include "bu/bitstring.h"
	13	#include "bu/exceptionbase.h"
	14	#include "bu/array.h"
	15	#include "bu/hash.h"
	16
	17	namespace Bu
	18	{
	19	class Stream;
	20	class MyriadStream;
	21
	22	subExceptionDeclBegin( MyriadException )
	23	enum
	24	{
	25	emptyStream,
	26	invalidFormat,
	27	badVersion,
	28	invalidWordSize,
	29	noSuchStream,
	30	streamExists,
	31	invalidStreamId,
	32	protectedStream
	33	};
	34	subExceptionDeclEnd();
	35
	36	/**
	37	* Myriad block-allocated stream multiplexing system. This is a system for
	38	* creating streams that contain other streams in a flexible and lightweight
	39	* manner. Basically, you can create a file (or any other stream) that can
	40	* store any number of flexible, growing streams. The streams within the
	41	* Myriad stream are automatically numbered, not named. This works more
	42	* or less like a filesystem, but without the extra layer for managing
	43	* file and directory links. This would actually be very easy to add
	44	* on top of Myriad, but is not required.
	45	*
	46	* Header format is as follows:
	47	*
	48	* MMMMvBssssSSSS*
	49	* M = Magic number (0AD3FA84)
	50	* v = version number
	51	* B = Bits per int
	52	* s = Blocksize in bytes
	53	* S = Number of Streams
	54	*
	55	* The * represents the Stream headers, one per stream, as follows:
	56	* IIIIssss$
	57	* I = Id number of the stream
	58	* s = size of stream in bytes
	59	*
	60	* The $ represents the Block headers, one per used block, as follows:
	61	* IIII
	62	* I = Index of the block
	63	*
	64	* The stream/block data is interleaved in the header, so all blocks stored
	65	* with one stream are together. The block headers are in order, and the
	66	* data in them is required to be "solid" you cannot fill partial blocks
	67	* mid-way through a stream.
	68	*
	69	* The initial block starts with the nids header, and is both the zero block
	70	* and the zero stream. For now, the minimum block size is the size needed
	71	* to store the base header, the zero stream header, and the first two
	72	* blocks of the zero stream, so 30 bytes. Since it's reccomended to use
	73	* a size that will fit evenly into filesystem blocks, then a size of 32 is
	74	* probably the smallest reccomended size because all powers of two equal
	75	* to or greater than 32 are evenly divisible by 32.
	76	*
	77	* I have had a thought that if the block size were smaller than 42 bytes
	78	* the header would consume the first N blocks where N * block size is
	79	* enough space to house the initial header, the first stream header, and
	80	* the first N block headers. This, of course, causes you to hit an
	81	* infinite header if the block size is small enough.
	82	*/
	83	class Myriad
	84	{
	85	friend class MyriadStream;
	86	public:
	87	/**
	88	* Create a Myriad object that uses the given stream to store data.
	89	* This stream must be random access. The block size and preallocate
	90	* values passed in are values that will be used if the given stream
	91	* is empty. In that case the stream will be "formatted" for myriad
	92	* with the specified block size. If there is already a viable Myriad
	93	* format present in the stream, then the blocksize and preallocate
	94	* values will be ignored and the values from the stream will be used
	95	* instead. If the stream doesn't appear to be Myriad formatted an
	96	* exception will be thrown.
	97	*/
	98	Myriad( Bu::Stream &sStore, int iBlockSize=512, int iPreallocate=8 );
	99	virtual ~Myriad();
	100
	101	/**
	102	* Destroy whatever data may be in the base stream and create a new
	103	* Myriad system there with the given blocksize. Use this with care,
	104	* it will destroy anything that was already in the stream, and
	105	* generally, should not ever have to be used.
	106	*/
	107	void initialize( int iBlockSize, int iPreAllocate=1 );
	108
	109	/**
	110	* Create a new stream within the Myriad system. The ID of the new
	111	* stream is returned.
	112	*/
	113	int createStream( int iPreAllocate=1 );
	114
	115	/**
	116	* Create a new stream within the Myriad system with a given id. The
	117	* id that you provide will be the new id of the stream unless it's
	118	* already used, in which case an error is thrown. This is primarilly
	119	* useful when copying an old Myriad file into a new one.
	120	*/
	121	int createStreamWithId( int iId, int iPreAllocate=1 );
	122
	123	/**
	124	* Delete a stream that's already within the Myriad.
	125	*/
	126	void deleteStream( int iId );
	127
	128	/**
	129	* Return a new Stream object assosiated with the given stream ID.
	130	*/
	131	MyriadStream openStream( int iId );
	132
	133	Bu::Array<int> getStreamIds();
	134	int getStreamSize( int iId );
	135	bool hasStream( int iId );
	136
	137	int getNumStreams();
	138	int getBlockSize();
	139	int getNumBlocks();
	140	int getNumUsedBlocks();
	141	int getTotalUsedBytes();
	142	int getTotalUnusedBytes();
	143	int getTotalUnusedBytes( int iFakeBlockSize );
	144
	145	/**
	146	* Syncronize the header data, etc. with the storage stream. It's not
	147	* a bad idea to call this periodically.
	148	*/
	149	void sync();
	150
	151	/**
	152	* Read the first few bytes from the given stream and return true/false
	153	* depending on weather or not it's a Myriad stream. This will throw
	154	* an exception if the stream is empty, or is not random access.
	155	*/
	156	static bool isMyriad( Bu::Stream &sStore );
	157
	158	const Bu::BitString &getBlocksUsed() const;
	159
	160	private:
	161	/**
	162	* Initialize this object based on the data already in the assosiated
	163	* stream. This will be called automatically for you if you forget,
	164	* but if you want to pre-initialize for some reason, just call this
	165	* once before you actually start doing anything with your Myriad.
	166	*/
	167	void initialize();
	168
	169	enum
	170	{
	171	blockUnused = 0xFFFFFFFFUL
	172	};
	173
	174	typedef Bu::Array<int> BlockArray;
	175	class Stream
	176	{
	177	public:
	178	int iId;
	179	int iSize;
	180	BlockArray aBlocks;
	181	};
	182	typedef Bu::Array<Stream *> StreamArray;
	183
	184	class Block
	185	{
	186	public:
	187	char *pData;
	188	bool bChanged;
	189	int iBlockIndex;
	190	};
	191
	192	void updateHeader();
	193	int findEmptyBlock();
	194
	195	/**
	196	*@todo Change this to use a binary search, it's nicer.
	197	*/
	198	Stream *findStream( int iId );
	199
	200	Block *getBlock( int iBlock );
	201	void releaseBlock( Block *pBlock );
	202	void syncBlock( Block *pBlock );
	203
	204	int streamAddBlock( Stream *pStream );
	205	void setStreamSize( Stream *pStream, long iSize );
	206
	207	void headerChanged();
	208
	209	private:
	210	Bu::Stream &sStore;
	211	int iBlockSize;
	212	int iBlocks;
	213	int iUsed;
	214	Bu::BitString bsBlockUsed;
	215	StreamArray aStreams;
	216	typedef Bu::Hash<int, Block *> BlockHash;
	217	BlockHash hActiveBlocks;
	218	bool bHeaderChanged;
	219	};
	220	};
	221
	222	#endif