return of venti

src/cmd/venti/srv/dat.h

@@ -0,0 +1,718 @@
+typedef struct Config		Config;
+typedef struct AMap		AMap;
+typedef struct AMapN		AMapN;
+typedef struct Arena		Arena;
+typedef struct AState	AState;
+typedef struct ArenaHead	ArenaHead;
+typedef struct ArenaPart	ArenaPart;
+typedef struct ArenaTail	ArenaTail;
+typedef struct ATailStats	ATailStats;
+typedef struct CIBlock		CIBlock;
+typedef struct Clump		Clump;
+typedef struct ClumpInfo	ClumpInfo;
+typedef struct Graph Graph;
+typedef struct IAddr		IAddr;
+typedef struct IBucket		IBucket;
+typedef struct IEStream		IEStream;
+typedef struct IEntry		IEntry;
+typedef struct IFile		IFile;
+typedef struct ISect		ISect;
+typedef struct Index		Index;
+typedef struct Lump		Lump;
+typedef struct DBlock		DBlock;
+typedef struct Part		Part;
+typedef struct Statbin Statbin;
+typedef struct Statdesc	Statdesc;
+typedef struct Stats		Stats;
+typedef struct ZBlock		ZBlock;
+typedef struct Round	Round;
+typedef struct Bloom	Bloom;
+
+#define TWID32	((u32int)~(u32int)0)
+#define TWID64	((u64int)~(u64int)0)
+#define	TWID8	((u8int)~(u8int)0)
+
+enum
+{
+	ABlockLog		= 9,		/* log2(512), the quantum for reading arenas */
+	ANameSize		= 64,
+	MaxDiskBlock		= 64*1024,	/* max. allowed size for a disk block */
+	MaxIoSize		= 64*1024,	/* max. allowed size for a disk io operation */
+	PartBlank		= 256*1024,	/* untouched section at beginning of partition */
+	HeadSize		= 512,		/* size of a header after PartBlank */
+	MinArenaSize		= 1*1024*1024,	/* smallest reasonable arena size */
+	IndexBase		= 1024*1024,	/* initial address to use in an index */
+	MaxIo			= 64*1024,	/* max size of a single read or write operation */
+	ICacheBits		= 16,		/* default bits for indexing icache */
+	ICacheDepth		= 4,		/* default depth of an icache hash chain */
+	MaxAMap			= 2*1024,	/* max. allowed arenas in an address mapping; must be < 32*1024 */
+
+	/*
+	 * return codes from syncarena
+	 */
+	SyncDataErr	= 1 << 0,		/* problem reading the clump data */
+	SyncCIErr	= 1 << 1,		/* found erroneous clump directory entries */
+	SyncCIZero	= 1 << 2,		/* found unwritten clump directory entries */
+	SyncFixErr	= 1 << 3,		/* error writing fixed data */
+	SyncHeader	= 1 << 4,		/* altered header fields */
+
+	/*
+	 * error severity
+	 */
+	EOk			= 0,		/* error expected in normal operation */
+	EStrange,				/* strange error that should be logged */
+	ECorrupt,				/* corrupted data found in arenas */
+	EICorrupt,				/* corrupted data found in index */
+	EAdmin,					/* should be brought to administrators' attention */
+	ECrash,					/* really bad internal error */
+	EBug,					/* a limitation which should be fixed */
+	EInconsist,				/* inconsistencies between index and arena */
+	EMax,
+
+	/*
+	 * internal disk formats for the venti archival storage system
+	 */
+	/*
+	 * magic numbers on disk
+	 */
+	_ClumpMagic		= 0xd15cb10c,	/* clump header, deprecated */
+	ClumpFreeMagic		= 0,		/* free clump; terminates active clump log */
+
+	ArenaPartMagic		= 0xa9e4a5e7,	/* arena partition header */
+	ArenaMagic		= 0xf2a14ead,	/* arena trailer */
+	ArenaHeadMagic		= 0xd15c4ead,	/* arena header */
+	
+	BloomMagic		= 0xb1004ead,	/* bloom filter header */
+	BloomMaxHash	= 32,
+
+	ISectMagic		= 0xd15c5ec7,	/* index header */
+
+	ArenaPartVersion	= 3,
+	ArenaVersion4		= 4,
+	ArenaVersion5		= 5,
+	BloomVersion		= 1,
+	IndexVersion		= 1,
+	ISectVersion1		= 1,
+	ISectVersion2		= 2,
+
+	/*
+	 * encodings of clumps on disk
+	 */
+	ClumpEErr		= 0,		/* can't happen */
+	ClumpENone,				/* plain */
+	ClumpECompress,				/* compressed */
+	ClumpEMax,
+
+	/*
+	 * sizes in bytes on disk
+	 */
+	U8Size			= 1,
+	U16Size			= 2,
+	U32Size			= 4,
+	U64Size			= 8,
+
+	ArenaPartSize		= 4 * U32Size,
+	ArenaSize4		= 2 * U64Size + 6 * U32Size + ANameSize + U8Size,
+	ArenaSize5			= ArenaSize4 + U32Size,
+	ArenaHeadSize4		= U64Size + 3 * U32Size + ANameSize,
+	ArenaHeadSize5		= ArenaHeadSize4 + U32Size,
+	BloomHeadSize	= 4 * U32Size,
+	ISectSize1		= 7 * U32Size + 2 * ANameSize,
+	ISectSize2		= ISectSize1 + U32Size,
+	ClumpInfoSize		= U8Size + 2 * U16Size + VtScoreSize,
+	ClumpSize		= ClumpInfoSize + U8Size + 3 * U32Size,
+	MaxBloomSize		= 1<<(32-3),	/* 2^32 bits */
+	MaxBloomHash	= 32,		/* bits per score */
+	/*
+	 * BUG - The various block copies that manipulate entry buckets
+	 * would be faster if we bumped IBucketSize up to 8 and IEntrySize up to 40,
+	 * so that everything is word-aligned.  Buildindex is actually cpu-bound
+	 * by the (byte at a time) copying in qsort.
+	 */
+	IBucketSize		= U32Size + U16Size,
+	IEntrySize		= U64Size + U32Size + 2*U16Size + 2*U8Size + VtScoreSize,
+	IEntryTypeOff		= VtScoreSize + U64Size + U32Size + 2 * U16Size,
+
+	MaxClumpBlocks		=  (VtMaxLumpSize + ClumpSize + (1 << ABlockLog) - 1) >> ABlockLog,
+
+	/*
+	 * dirty flags - order controls disk write order
+	 */
+	DirtyArena		= 1,
+	DirtyArenaCib,
+	DirtyArenaTrailer,
+	DirtyMax,
+
+	VentiZZZZZZZZ
+};
+
+extern char TraceDisk[];
+extern char TraceLump[];
+extern char TraceBlock[];
+extern char TraceProc[];
+extern char TraceWork[];
+extern char TraceQuiet[];
+extern char TraceRpc[];
+
+/*
+ * results of parsing and initializing a config file
+ */
+struct Config
+{
+	char		*index;			/* name of the index to initialize */
+	int		naparts;		/* arena partitions initialized */
+	ArenaPart	**aparts;
+	int		nsects;			/* index sections initialized */
+	ISect		**sects;
+	Bloom	*bloom;		/* bloom filter */
+	u32int	bcmem;
+	u32int	mem;
+	u32int	icmem;
+	int		queuewrites;
+	char*	haddr;
+	char*	vaddr;
+	char*	webroot;
+};
+
+/*
+ * a Part is the low level interface to files or disks.
+ * there are two main types of partitions
+ *	arena paritions, which some number of arenas, each in a sub-partition.
+ *	index partition, which only have one subpartition.
+ */
+struct Part
+{
+	int		fd;			/* rock for accessing the disk */
+	int		mode;
+	u64int		offset;
+	u64int		size;			/* size of the partiton */
+	u32int		blocksize;		/* block size for reads and writes */
+	u32int		fsblocksize;	/* minimum file system block size */
+	char		*name;
+	char		*filename;
+	Channel		*writechan;		/* chan[dcache.nblock](DBlock*) */
+};
+
+/*
+ * a cached block from the partition
+ * yuck -- most of this is internal structure for the cache
+ * all other routines should only use data
+ */
+struct DBlock
+{
+	u8int	*data;
+
+	Part	*part;			/* partition in which cached */
+	u64int	addr;			/* base address on the partition */
+	u32int	size;			/* amount of data available, not amount allocated; should go away */
+	u32int	mode;
+	u32int	dirty;
+	u32int	dirtying;
+	DBlock	*next;			/* doubly linked hash chains */
+	DBlock	*prev;
+	u32int	heap;			/* index in heap table */
+	u32int	used;			/* last reference times */
+	u32int	used2;
+	u32int	ref;			/* reference count */
+	RWLock	lock;			/* for access to data only */
+	Channel	*writedonechan;	
+	void*	chanbuf[1];		/* buffer for the chan! */
+};
+
+/*
+ * a cached block from the partition
+ * yuck -- most of this is internal structure for the cache
+ * all other routines should only use data
+ * double yuck -- this is mostly the same as a DBlock
+ */
+struct Lump
+{
+	Packet	*data;
+
+	Part	*part;			/* partition in which cached */
+	u8int	score[VtScoreSize];	/* score of packet */
+	u8int	type;			/* type of packet */
+	u32int	size;			/* amount of data allocated to hold packet */
+	Lump	*next;			/* doubly linked hash chains */
+	Lump	*prev;
+	u32int	heap;			/* index in heap table */
+	u32int	used;			/* last reference times */
+	u32int	used2;
+	u32int	ref;			/* reference count */
+	QLock	lock;			/* for access to data only */
+};
+
+/*
+ * mapping between names and address ranges
+ */
+struct AMap
+{
+	u64int		start;
+	u64int		stop;
+	char		name[ANameSize];
+};
+
+/*
+ * an AMap along with a length
+ */
+struct AMapN
+{
+	int		n;
+	AMap		*map;
+};
+
+/*
+ * an ArenaPart is a partition made up of Arenas
+ * it exists because most os's don't support many partitions,
+ * and we want to have many different Arenas
+ */
+struct ArenaPart
+{
+	Part		*part;
+	u64int		size;			/* size of underlying partition, rounded down to blocks */
+	Arena		**arenas;
+	u32int		tabbase;		/* base address of arena table on disk */
+	u32int		tabsize;		/* max. bytes in arena table */
+
+	/*
+	 * fields stored on disk
+	 */
+	u32int		version;
+	u32int		blocksize;		/* "optimal" block size for reads and writes */
+	u32int		arenabase;		/* base address of first arena */
+
+	/*
+	 * stored in the arena mapping table on disk
+	 */
+	AMap		*map;
+	int		narenas;
+};
+
+/*
+ * info about one block in the clump info cache
+ */
+struct CIBlock
+{
+	u32int		block;			/* blocks in the directory */
+	int		offset;			/* offsets of one clump in the data */
+	DBlock		*data;
+};
+
+/*
+ * Statistics kept in the tail. 
+ */
+struct ATailStats
+{
+	u32int		clumps;		/* number of clumps */
+	u32int		cclumps;		/* number of compressed clumps */
+	u64int		used;
+	u64int		uncsize;
+	u8int		sealed;
+};
+
+/*
+ * Arena state - represents a point in the data log
+ */
+struct AState
+{
+	Arena		*arena;
+	u64int		aa;			/* index address */
+	ATailStats		stats;
+};
+
+/*
+ * an Arena is a log of Clumps, preceeded by an ArenaHeader,
+ * and followed by a Arena, each in one disk block.
+ * struct on disk is not always up to date, but should be self-consistent.
+ * to sync after reboot, follow clumps starting at used until ClumpFreeMagic if found.
+ * <struct name="Arena" type="Arena *">
+ *	<field name="name" val="s->name" type="AName"/>
+ *	<field name="version" val="s->version" type="U32int"/>
+ *	<field name="partition" val="s->part->name" type="AName"/>
+ *	<field name="blocksize" val="s->blocksize" type="U32int"/>
+ *	<field name="start" val="s->base" type="U64int"/>
+ *	<field name="stop" val="s->base+2*s->blocksize" type="U64int"/>
+ *	<field name="created" val="s->ctime" type="U32int"/>
+ *	<field name="modified" val="s->wtime" type="U32int"/>
+ *	<field name="sealed" val="s->sealed" type="Sealed"/>
+ *	<field name="score" val="s->score" type="Score"/>
+ *	<field name="clumps" val="s->clumps" type="U32int"/>
+ *	<field name="compressedclumps" val="s->cclumps" type="U32int"/>
+ *	<field name="data" val="s->uncsize" type="U64int"/>
+ *	<field name="compresseddata" val="s->used - s->clumps * ClumpSize" type="U64int"/>
+ *	<field name="storage" val="s->used + s->clumps * ClumpInfoSize" type="U64int"/>
+ * </struct>
+ */
+struct Arena
+{
+	QLock		lock;			/* lock for arena fields, writing to disk */
+	Part		*part;			/* partition in which arena lives */
+	int		blocksize;		/* size of block to read or write */
+	u64int		base;			/* base address on disk */
+	u64int		size;			/* total space in the arena */
+	u64int		limit;			/* storage limit for clumps */
+	u8int		score[VtScoreSize];	/* score of the entire sealed & summed arena */
+
+	int		clumpmax;		/* ClumpInfos per block */
+	AState		mem;
+	int		inqueue;
+	DigestState	sha1;
+
+	/*
+	 * fields stored on disk
+	 */
+	u32int		version;
+	char		name[ANameSize];	/* text label */
+	ATailStats		memstats;
+	ATailStats		diskstats;
+	u32int		ctime;			/* first time a block was written */
+	u32int		wtime;			/* last time a block was written */
+	u32int		clumpmagic;
+};
+
+/*
+ * redundant storage of some fields at the beginning of each arena
+ */
+struct ArenaHead
+{
+	u32int		version;
+	char		name[ANameSize];
+	u32int		blocksize;
+	u64int		size;
+	u32int		clumpmagic;
+};
+
+/*
+ * most interesting meta information for a clump.
+ * stored in each clump's header and in the Arena's directory,
+ * stored in reverse order just prior to the arena trailer
+ */
+struct ClumpInfo
+{
+	u8int		type;
+	u16int		size;			/* size of disk data, not including header */
+	u16int		uncsize;		/* size of uncompressed data */
+	u8int		score[VtScoreSize];	/* score of the uncompressed data only */
+};
+
+/*
+ * header for an immutable clump of data
+ */
+struct Clump
+{
+	ClumpInfo	info;
+	u8int		encoding;
+	u32int		creator;		/* initial client which wrote the block */
+	u32int		time;			/* creation at gmt seconds since 1/1/1970 */
+};
+
+/*
+ * index of all clumps according to their score
+ * this is just a wrapper to tie together the index sections
+ * <struct name="Index" type="Index *">
+ *	<field name="name" val="s->name" type="AName"/>
+ *	<field name="version" val="s->version" type="U32int"/>
+ *	<field name="blocksize" val="s->blocksize" type="U32int"/>
+ *	<field name="tabsize" val="s->tabsize" type="U32int"/>
+ *	<field name="buckets" val="s->buckets" type="U32int"/>
+ *	<field name="buckdiv" val="s->div" type="U32int"/>
+ *	<field name="bitblocks" val="s->div" type="U32int"/>
+ *	<field name="maxdepth" val="s->div" type="U32int"/>
+ *	<field name="bitkeylog" val="s->div" type="U32int"/>
+ *	<field name="bitkeymask" val="s->div" type="U32int"/>
+ *	<array name="sect" val="&s->smap[i]" elems="s->nsects" type="Amap"/>
+ *	<array name="amap" val="&s->amap[i]" elems="s->narenas" type="Amap"/>
+ *	<array name="arena" val="s->arenas[i]" elems="s->narenas" type="Arena"/>
+ * </struct>
+ * <struct name="Amap" type="AMap *">
+ *	<field name="name" val="s->name" type="AName"/>
+ *	<field name="start" val="s->start" type="U64int"/>
+ *	<field name="stop" val="s->stop" type="U64int"/>
+ * </struct>
+ */
+struct Index
+{
+	u32int		div;			/* divisor for mapping score to bucket */
+	u32int		buckets;		/* last bucket used in disk hash table */
+	u32int		blocksize;
+	u32int		tabsize;		/* max. bytes in index config */
+	u32int		bitblocks;	//XXX remove these fields
+	u32int		maxdepth;
+	u32int		bitkeylog;
+	u32int		bitkeymask;
+
+	int		mapalloc;		/* first arena to check when adding a lump */
+	Arena		**arenas;		/* arenas in the mapping */
+	ISect		**sects;		/* sections which hold the buckets */
+	Bloom		*bloom;	/* bloom filter */
+
+	/*
+	 * fields stored in config file 
+	 */
+	u32int		version;
+	char		name[ANameSize];	/* text label */
+	int		nsects;
+	AMap		*smap;			/* mapping of buckets to index sections */
+	int		narenas;
+	AMap		*amap;			/* mapping from index addesses to arenas */
+};
+
+/*
+ * one part of the bucket storage for an index.
+ * the index blocks are sequentially allocated
+ * across all of the sections.
+ */
+struct ISect
+{
+	Part		*part;
+	int		blocklog;		/* log2(blocksize) */
+	int		buckmax;		/* max. entries in a index bucket */
+	u32int		tabbase;		/* base address of index config table on disk */
+	u32int		tabsize;		/* max. bytes in index config */
+	Channel	*writechan;
+	Channel	*writedonechan;
+
+	/*
+	 * fields stored on disk
+	 */
+	u32int		version;
+	u32int		bucketmagic;
+	char		name[ANameSize];	/* text label */
+	char		index[ANameSize];	/* index owning the section */
+	u32int		blocksize;		/* size of hash buckets in index */
+	u32int		blockbase;		/* address of start of on disk index table */
+	u32int		blocks;			/* total blocks on disk; some may be unused */
+	u32int		start;			/* first bucket in this section */
+	u32int		stop;			/* limit of buckets in this section */
+};
+
+/*
+ * externally interesting part of an IEntry
+ */
+struct IAddr
+{
+	u64int		addr;
+	u16int		size;			/* uncompressed size */
+	u8int		type;			/* type of block */
+	u8int		blocks;			/* arena io quanta for Clump + data */
+};
+
+/*
+ * entries in the index
+ * kept in IBuckets in the disk index table,
+ * cached in the memory ICache.
+ */
+struct IEntry
+{
+	u8int		score[VtScoreSize];
+	IEntry		*next;			/* next in hash chain */
+	IEntry		*nextdirty; 		/* next in dirty chain */
+	u32int		wtime;			/* last write time */
+	u16int		train;			/* relative train containing the most recent ref; 0 if no ref, 1 if in same car */
+	u8int		rac;			/* read ahead count */
+	u8int		dirty;		/* is dirty */
+	IAddr		ia;
+};
+
+/*
+ * buckets in the on disk index table
+ */
+struct IBucket
+{
+	u16int		n;			/* number of active indices */
+	u32int		buck;		/* used by buildindex/checkindex only */
+	u8int		*data;
+};
+
+/*
+ * temporary buffers used by individual threads
+ */
+struct ZBlock
+{
+	u32int		len;
+	u32int		_size;
+	u8int		*data;
+	u8int		*free;
+};
+
+/*
+ * simple input buffer for a '\0' terminated text file
+ */
+struct IFile
+{
+	char		*name;				/* name of the file */
+	ZBlock		*b;				/* entire contents of file */
+	u32int		pos;				/* current position in the file */
+};
+
+struct Statdesc
+{
+	char *name;
+	ulong max;
+};
+
+/* keep in sync with stats.c:/statdesc and httpd.c:/graphname*/
+enum
+{
+	StatRpcTotal,
+	StatRpcRead,
+	StatRpcReadOk,
+	StatRpcReadFail,
+	StatRpcReadBytes,
+	StatRpcReadTime,
+	StatRpcReadCached,
+	StatRpcReadCachedTime,
+	StatRpcReadUncached,
+	StatRpcReadUncachedTime,
+	StatRpcWrite,
+	StatRpcWriteNew,
+	StatRpcWriteOld,
+	StatRpcWriteFail,
+	StatRpcWriteBytes,
+	StatRpcWriteTime,
+	StatRpcWriteNewTime,
+	StatRpcWriteOldTime,
+
+	StatLcacheHit,
+	StatLcacheMiss,
+	StatLcacheRead,
+	StatLcacheWrite,
+	StatLcacheSize,
+	StatLcacheStall,
+	StatLcacheReadTime,
+
+	StatDcacheHit,
+	StatDcacheMiss,
+	StatDcacheLookup,
+	StatDcacheRead,
+	StatDcacheWrite,
+	StatDcacheDirty,
+	StatDcacheSize,
+	StatDcacheFlush,
+	StatDcacheStall,
+	StatDcacheLookupTime,
+
+	StatDblockStall,
+	StatLumpStall,
+
+	StatIcacheHit,
+	StatIcacheMiss,
+	StatIcacheRead,
+	StatIcacheWrite,
+	StatIcacheFill,
+	StatIcachePrefetch,
+	StatIcacheDirty,
+	StatIcacheSize,
+	StatIcacheFlush,
+	StatIcacheStall,
+	StatIcacheReadTime,
+
+	StatBloomHit,
+	StatBloomMiss,
+	StatBloomFalseMiss,
+	StatBloomLookup,
+	StatBloomOnes,
+	StatBloomBits,
+	StatBloomLookupTime,
+
+	StatApartRead,
+	StatApartReadBytes,
+	StatApartWrite,
+	StatApartWriteBytes,
+
+	StatIsectRead,
+	StatIsectReadBytes,
+	StatIsectWrite,
+	StatIsectWriteBytes,
+
+	StatSumRead,
+	StatSumReadBytes,
+
+	NStat
+};
+
+extern Statdesc statdesc[NStat];
+
+/*
+ * statistics about the operation of the server
+ * mainly for performance monitoring and profiling.
+ */
+struct Stats
+{
+	ulong		now;
+	ulong		n[NStat];
+};
+
+struct Statbin
+{
+	uint nsamp;
+	uint min;
+	uint max;
+	uint avg;
+};
+
+struct Graph
+{
+	long (*fn)(Stats*, Stats*, void*);
+	void *arg;
+	long t0;
+	long t1;
+	long min;
+	long max;
+	long wid;
+	long ht;
+	int fill;
+};
+
+/*
+ * for kicking background processes that run one round after another after another
+ */
+struct Round
+{
+	QLock	lock;
+	Rendez	start;
+	Rendez	finish;
+	Rendez	delaywait;
+	int		delaytime;
+	int		delaykick;
+	char*	name;
+	int		last;
+	int		current;
+	int		next;
+	int		doanother;
+};
+
+/*
+ * Bloom filter of stored block hashes
+ */
+struct Bloom
+{
+	RWLock lk;		/* protects nhash, nbits, tab, mb */
+	QLock mod;		/* one marker at a time, protects nb */
+	int nhash;
+	ulong size;		/* bytes in tab */
+	ulong mask;		/* to produce index */
+	u8int *data;
+	Part *part;
+	Channel *writechan;
+	Channel *writedonechan;
+};
+
+extern	Index		*mainindex;
+extern	u32int		maxblocksize;		/* max. block size used by any partition */
+extern	int		paranoid;		/* should verify hashes on disk read */
+extern	int		queuewrites;		/* put all lump writes on a queue and finish later */
+extern	int		readonly;		/* only allowed to read the disk data */
+extern	Stats		stats;
+extern	u8int		zeroscore[VtScoreSize];
+extern	int		compressblocks;
+extern	int		writestodevnull;	/* dangerous - for performance debugging */
+extern	int		collectstats;
+extern	QLock	memdrawlock;
+extern	int		icachesleeptime;
+extern	int		arenasumsleeptime;
+
+#ifndef PLAN9PORT
+#pragma varargck type "V" uchar*
+#define ODIRECT 0
+#endif