db_arena.h

#pragma once

#include "db_error.h"
#include "db_redblack.h"

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif

#define MAX_segs  1000
#define MIN_segbits	 17
#define MIN_segsize  (1ULL << MIN_segbits)
#define MAX_segsize  (1ULL << (32 + 4))  // 32 bit offset and 4 bit multiplier

#define MAX_path  4096
#define MAX_blk		49	// max arena blk size in half bits
#define MAX_sys			5	// max user frame type
#define MAX_usr		32	// max user frame type

//  disk arena segment

typedef struct {
	uint64_t off;		// file offset of segment
	uint64_t size;		// size of the segment
	DbAddr nextObject;	// next Object address
	uint32_t maxId;		// highest object ID in use
} DbSeg;

//  arena creation specifications
//	data is permanent in database arena

typedef struct {
	uint64_t id;				// our id in parent's child list
	uint64_t nxtVer;			// next arena version when creating
	uint64_t childId;			// highest child Id we've issued
	uint64_t creation;			// milliseconds since 1/1/70
	uint32_t clntSize;			// extra client space allocated in hndlMap
  uint32_t arenaXtra;			// shared space after DbArena (DocStore, DbIndex)
	uint32_t objSize;			// size of ObjectId array slot
  uint32_t xtraSize;  // extra handle space after Handle
  uint8_t arenaType;          // type of the arena
	uint8_t sysTypes;			// number of system frame types
	uint8_t numTypes;			// number of user node frame types
	uint8_t dead[1];			// arena file killed/deleted
	DbAddr nameTree[1];			// child arena name red/black tree
	DbAddr childList[1];		// array of childId to arenaDef RbAddr
	DbAddr hndlArray[1];		// array of handle ids for this arena
	Params params[MaxParam];	// parameter array for rest of object
} ArenaDef;

//	system object types

typedef enum {
	freeFrame = 1,			// frames
	freeObjId,					// 
} SYSFrame;

typedef struct {
  DbAddr headFrame[1];	// FIFO queue head
  DbAddr freeFrame[1];	// available free objects
  DbAddr tailFrame[1];	// waiting for timestamp to expire
} TriadQueue;

//  arena at beginning of seg zero

typedef struct {
	DbSeg segs[MAX_segs]; 			// segment meta-data
	uint64_t lowTs, delTs, nxtTs;	// low hndl ts, Incr on delete

	DbAddr rbAddr[1];				// address of r/b entry
  TriadQueue blkFrame[MAX_blk];	// system created frames of objects 1/2 bit
  TriadQueue usrFrame[MAX_usr];	// user object frames 
  TriadQueue sysFrame[MAX_sys];	// system objects frames 
//	uint64_t objCount;				// overall number of objects
	uint64_t objSpace;				// overall size of objects
	uint32_t baseSize;				// client space after DbArena (DbIndex, DocStore)
	uint32_t objSize;				// size of ObjectId array slot
	uint16_t currSeg;				// index of highest segment
	uint16_t objSeg;				// current segment index for ObjIds
	volatile uint8_t mutex[1];					// arena allocation lock/drop flag
	uint8_t type[1];					// arena type
	uint8_t filler[128];
} DbArena;

//	per instance arena map structure
//	created when map is opened

struct DbMap_ {
	char *base[MAX_segs];	// pointers to mapped segment memory
#ifndef _WIN32
	int hndl;				// OS file handle
#else
	HANDLE hndl;
	HANDLE maphndl[MAX_segs];
#endif
	DbArena *arena;			// ptr to mapped seg zero
	char *arenaPath;		// file database path
	DbMap *parent, *db;		// ptr to parent and database
	ArenaDef *arenaDef;		// database configuration
	DbAddr childMaps[1];	// skipList of child DbMaps
	RedBlack *rbEntry;		// redblack entry address
  char *name;				// inMem map name
	uint32_t openCnt[1];	// count of open children
	uint32_t objSize;		// size of ObjectId array slot
	uint16_t pathLen;		// length of arena path
	uint16_t numSeg;		// number of mapped segments
	uint8_t mapMutex[1];		// segment mapping mutex
	uint8_t drop[1];			// arena map being killed
	uint8_t type[1];			// arena type
};

#define skipSize(addr) (((1ULL << addr->type) - sizeof(SkipNode)) / sizeof(SkipEntry))

#define SKIP_node 15

//	catalog structure

typedef struct {
  ObjId objId[65536];
} IdxSeg;

typedef struct {
	DbAddr databases[1];	// database names in the catalog
//	uint32_t maxEntry[1];
//	uint32_t numEntries[1];
//	DbAddr segAddr[1];		// preload fractions
} Catalog;

Catalog *catalog;

/**
 * open/create arenas
 */

DbMap *openMap(DbMap *parent, char *name, uint32_t nameLen, ArenaDef *arena, RedBlack *entry);
DbMap *arenaRbMap(DbMap *parent, RedBlack *entry);

RedBlack *procParam(DbMap *parent, char *name, int nameLen, Params *params);
DbMap *initArena (DbMap *map, ArenaDef *arenaDef, char *name, uint32_t nameLen, RedBlack *rbEntry);

/**
 *  memory mapping
 */

void* mapMemory(DbMap *map, uint64_t offset, uint64_t size, uint32_t segNo);
void unmapSeg(DbMap *map, uint32_t segNo);
bool mapSeg(DbMap *map, uint32_t segNo);
bool newSeg(DbMap *map, uint32_t minSize);
DbStatus dropMap(DbMap *db, bool dropDefs);

void getPath(DbMap *map, char *name, uint32_t nameLen, uint64_t ver);

uint32_t addPath(char *path, uint32_t len, char *name, uint32_t nameLen, uint64_t ver);