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Diffstat (limited to 'src/cmd/venti/dat.h')
| -rw-r--r-- | src/cmd/venti/dat.h | 497 |
1 files changed, 497 insertions, 0 deletions
diff --git a/src/cmd/venti/dat.h b/src/cmd/venti/dat.h new file mode 100644 index 00000000..b9f395c8 --- /dev/null +++ b/src/cmd/venti/dat.h @@ -0,0 +1,497 @@ +typedef struct Config Config; +typedef struct AMap AMap; +typedef struct AMapN AMapN; +typedef struct Arena Arena; +typedef struct ArenaHead ArenaHead; +typedef struct ArenaPart ArenaPart; +typedef struct CIBlock CIBlock; +typedef struct Clump Clump; +typedef struct ClumpInfo ClumpInfo; +typedef struct IAddr IAddr; +typedef struct IBucket IBucket; +typedef struct ICache ICache; +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 Stats Stats; +typedef struct ZBlock ZBlock; + +#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 */ + ClumpFreeMagic = 0, /* free clump; terminates active clump log */ + + ArenaPartMagic = 0xa9e4a5e7, /* arena partition header */ + ArenaMagic = 0xf2a14ead, /* arena trailer */ + ArenaHeadMagic = 0xd15c4ead, /* arena header */ + + ISectMagic = 0xd15c5ec7, /* index header */ + + ArenaPartVersion = 3, + ArenaVersion = 4, + IndexVersion = 1, + ISectVersion = 1, + + /* + * encodings of clumps on disk + */ + ClumpEErr = 0, /* can't happen */ + ClumpENone, /* plain */ + ClumpECompress, /* compressed */ + ClumpEMax, + + /* + * marker for corrupted data on disk + */ + VtTypeCorrupt = VtMaxType, + + /* + * sizes in bytes on disk + */ + U8Size = 1, + U16Size = 2, + U32Size = 4, + U64Size = 8, + + ArenaPartSize = 4 * U32Size, + ArenaSize = 2 * U64Size + 6 * U32Size + ANameSize + U8Size, + ArenaHeadSize = U64Size + 3 * U32Size + ANameSize, + ISectSize = 7 * U32Size + 2 * ANameSize, + ClumpInfoSize = U8Size + 2 * U16Size + VtScoreSize, + ClumpSize = ClumpInfoSize + U8Size + 3 * U32Size, + IBucketSize = U32Size + U16Size, + IEntrySize = U64Size + U32Size + 2*U16Size + 2*U8Size + VtScoreSize, + IEntryTypeOff = VtScoreSize + U64Size + U32Size + 2 * U16Size, + + MaxClumpBlocks = (VtMaxLumpSize + ClumpSize + (1 << ABlockLog) - 1) >> ABlockLog, + + VentiZZZZZZZZ +}; + +/* + * 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; +}; + +/* + * 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 */ + u64int size; /* size of the partiton */ + u32int blocksize; /* block size for reads and writes */ + char *name; +}; + +/* + * 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 */ + u16int size; /* amount of data available, not amount allocated; should go away */ + 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 */ + QLock lock; /* for access to data only */ +}; + +/* + * 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 */ + u16int 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; +}; + +/* + * 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 */ + CIBlock cib; /* dirty clump directory block */ + + /* + * fields stored on disk + */ + u32int version; + char name[ANameSize]; /* text label */ + u32int clumps; /* number of allocated clumps */ + u32int cclumps; /* clumps which are compressed; informational only */ + u32int ctime; /* first time a block was written */ + u32int wtime; /* last time a block was written */ + u64int used; /* number of bytes currently used */ + u64int uncsize; /* total of all clumps's uncsize; informational only */ + u8int sealed; /* arena all filled up? */ +}; + +/* + * redundant storage of some fields at the beginning of each arena + */ +struct ArenaHead +{ + u32int version; + char name[ANameSize]; + u32int blocksize; + u64int size; +}; + +/* + * 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"/> + * <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 */ + int mapalloc; /* first arena to check when adding a lump */ + Arena **arenas; /* arenas in the mapping */ + ISect **sects; /* sections which hold the buckets */ + + /* + * 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 */ + + /* + * fields stored on disk + */ + u32int version; + 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 */ + 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 */ + IAddr ia; +}; + +/* + * buckets in the on disk index table + */ +struct IBucket +{ + u16int n; /* number of active indices */ + u32int next; /* overflow bucket */ + u8int *data; +}; + +/* + * temporary buffers used by individual threads + */ +struct ZBlock +{ + u32int len; + u8int *data; +}; + +/* + * 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 */ +}; + +/* + * statistics about the operation of the server + * mainly for performance monitoring and profiling. + */ +struct Stats +{ + QLock lock; + long lumpwrites; /* protocol block writes */ + long lumpreads; /* protocol block reads */ + long lumphit; /* lump cache hit */ + long lumpmiss; /* lump cache miss */ + long clumpwrites; /* clumps to disk */ + vlong clumpbwrites; /* clump data bytes to disk */ + vlong clumpbcomp; /* clump bytes compressed */ + long clumpreads; /* clumps from disk */ + vlong clumpbreads; /* clump data bytes from disk */ + vlong clumpbuncomp; /* clump bytes uncompressed */ + long ciwrites; /* clump directory to disk */ + long cireads; /* clump directory from disk */ + long indexwrites; /* index to disk */ + long indexreads; /* index from disk */ + long indexwreads; /* for writing a new entry */ + long indexareads; /* for allocating an overflow block */ + long diskwrites; /* total disk writes */ + long diskreads; /* total disk reads */ + vlong diskbwrites; /* total disk bytes written */ + vlong diskbreads; /* total disk bytes read */ + long pchit; /* partition cache hit */ + long pcmiss; /* partition cache miss */ + long pcreads; /* partition cache reads from disk */ + vlong pcbreads; /* partition cache bytes read */ + long icinserts; /* stores into index cache */ + long iclookups; /* index cache lookups */ + long ichits; /* hits in the cache */ + long icfills; /* successful fills from index */ +}; + +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]; |