Library ebase_lib

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Classes

EbError

EbError is the exception class that is thrown by ebase.

EbIndexDef

EbIndexDef allows applications to construct or query about an index definition in Ebase. In ebase, an index can be defined based on multiple fields. Applications cannot modify the index definition if the definition already exists in ebase.

EbRecord

EbRecord is a class that allows one to retrieve and modify field data in a record. It is also used to create a new record.

EbSearch

EbSearch is a client-level module that provides single field based search functions.

Ebase

The embedded database engine class.

EbaseDef

EbaseDef is a class that let apps to construct a definition used to created Ebase database file. It can also be used to query the structure of an existing Ebase database.

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Data

typedef EbUint8 EbIndexId;

enum EbDataType ;

enum EbErrorEnum ;

const char EB_RECORD_ID[];

typedef enum EbResult;

typedef enum EbBoolean;

typedef signed char EbInt8;

typedef unsigned char EbUint8;

typedef signed short EbInt16;

typedef unsigned short EbUint16;

typedef int EbInt32;

typedef unsigned int EbUint32;

typedef EbUint16 EbDataHandle;

const EbDataHandle EB_INVALID_HANDLE == (EbDataHandle)-1;

const EbInt32 EB_MAGIC_WORD_LENGTH = 4;

const EbUint8 EB_MAJOR_NUMBER = 1;

const EbUint8 EB_MINOR_NUMBER = 0;

const EbUint32 EB_MAX_NUM_INDEX_FIELDS = 4;

const EbUint32 EB_MAX_FIELD_NAME = 30;

const EbUint32 EB_MAX_ENCODED_FIELD_SIZE = 255;

const EbUint32 EB_MAX_NUM_INDICES = 255;

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Global Functions

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QUICK GUIDE

• Data ownership
  Applications exchange data with ebase through data pointers. At any time, either the application or ebase owns a piece of data, but never both. The ownership of a piece implies that the owner must free the memory space occupied by the data if the data is no longer needed or when the owner is being deleted. Data created by applications belong to applications. So are true with data created by ebase. The only exceptions are listed as follows :
  • When applications call EbRecord::PutFieldxxx(), the applications loose the ownership.
  • When applications call EbRecord::GetFieldxxxAlloc(), the applications own the data pointed by the return pointers.
• More to be added ...

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typedef EbUint8 EbIndexId;

Index Id type. Used to identify an index in an open database.

typedef EbUint8 EbIndexId;

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enum EbDataType ;

Data types supported in Ebase. (To be expanded in the future.)

enum EbDataType {
    EB_INT32,           // EbInt32
    EB_STRING,          // char *
    EB_RAW              // void * plus a size parameter
};

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enum EbErrorEnum ;

Exceptions Return by Ebase functions. In this implementation, we use C++ exception mechanism.

enum EbErrorEnum {
    EBE_FAIL = 3,
    EBE_OPEN_FILE = 1,
    EBE_OUT_OF_MEMORY = 2,
    EBE_OUT_OF_FILE_SPACE = 6,
    EBE_DATA_DRIVER_NOT_FOUND = 4,
    EBE_FIELD_TYPE_MISMATCH = 7,
    EBE_INVALID_FIELD = 8,
    EBE_INVALID_INDEX = 9,
    EBE_INVALID_RECORD = 10,
    EBE_ACCESS_VIOLATION = 11,
    EBE_DATABASE_NOT_OPEN = 12,
};

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const char EB_RECORD_ID[];

String constants used in ebase

extern const char EB_RECORD_ID[];       // "RecordId"

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typedef enum EbResult;

A boolean type used to check if a function call is successful.

typedef enum {
    EB_SUCCESS = 1,
    EB_FAILURE = 0
} EbResult;

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typedef enum EbBoolean;

Ebase boolean type.

typedef enum {
    EB_TRUE  = 1,
    EB_FALSE = 0
} EbBoolean;

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typedef signed char EbInt8;

typedef         signed char     EbInt8;

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typedef unsigned char EbUint8;

typedef         unsigned char   EbUint8;

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typedef signed short EbInt16;

typedef         signed short    EbInt16;

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typedef unsigned short EbUint16;

typedef         unsigned short  EbUint16;

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typedef int EbInt32;

typedef         int             EbInt32;

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typedef unsigned int EbUint32;

typedef         unsigned int    EbUint32;

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typedef EbUint16 EbDataHandle;

The EbDataHandle type. It is currently EbUint16, which implies a file can have no more than 64k number of data.

typedef         EbUint16          EbDataHandle;

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const EbDataHandle EB_INVALID_HANDLE = (EbDataHandle)-1;

The bad (invalid) data handle.

const   EbDataHandle EB_INVALID_HANDLE = (EbDataHandle)-1;

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const EbInt32 EB_MAGIC_WORD_LENGTH = 4;

The magic word length for data file.

const EbInt32 EB_MAGIC_WORD_LENGTH = 4;

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const EbUint8 EB_MAJOR_NUMBER = 1;

database major versoin number

const EbUint8 EB_MAJOR_NUMBER = 1;

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const EbUint8 EB_MINOR_NUMBER = 0;

database minor versoin number

const EbUint8 EB_MINOR_NUMBER = 0;

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const EbUint32 EB_MAX_NUM_INDEX_FIELDS = 4;

the maximum number of fields that can be definied in a generic index driver. (Database-specific index driver is not subject to this constraint.)

const EbUint32 EB_MAX_NUM_INDEX_FIELDS = 4;

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const EbUint32 EB_MAX_FIELD_NAME = 30;

maximum number of chars in field name

const EbUint32 EB_MAX_FIELD_NAME = 30;

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const EbUint32 EB_MAX_ENCODED_FIELD_SIZE = 255;

the maximum length of an encoded data. An encoded data is embedded into the record. It is currently 255, because the encoded field size is uint8.

const EbUint32 EB_MAX_ENCODED_FIELD_SIZE = 255;

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const EbUint32 EB_MAX_NUM_INDICES = 255;

the maximum number of indices

const EbUint32 EB_MAX_NUM_INDICES = 255;

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