simpledb.record
Class TableInfo

java.lang.Object
  simpledb.record.TableInfo

public class TableInfo
extends Object

The metadata about a table and its records.

Author:

Edward Sciore

Constructor Summary

TableInfo(String tblname, Schema schema)
Creates a TableInfo object, given a table name and schema.

TableInfo(String tblname, Schema schema, Map<String,Integer> offsets, int recordlen)
Creates a TableInfo object from the specified metadata.

Method Summary

String	fileName() Returns the filename assigned to this table.
int	offset(String fldname) Returns the offset of a specified field within a record
int	recordLength() Returns the length of a record, in bytes.
Schema	schema() Returns the schema of the table's records

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TableInfo

public TableInfo(String tblname,
                 Schema schema)

Creates a TableInfo object, given a table name and schema. The constructor calculates the physical offset of each field. This constructor is used when a table is created.

Parameters:

tblname - the name of the table

schema - the schema of the table's records

TableInfo

public TableInfo(String tblname,
                 Schema schema,
                 Map<String,Integer> offsets,
                 int recordlen)

Creates a TableInfo object from the specified metadata. This constructor is used when the metadata is retrieved from the catalog.

Parameters:

tblname - the name of the table

schema - the schema of the table's records

offsets - the already-calculated offsets of the fields within a record

recordlen - the already-calculated length of each record

Method Detail

fileName

public String fileName()

Returns the filename assigned to this table. Currently, the filename is the table name followed by ".tbl".

Returns:

the name of the file assigned to the table

schema

public Schema schema()

Returns the schema of the table's records

Returns:

the table's record schema

offset

public int offset(String fldname)

Returns the offset of a specified field within a record

Parameters:

fldname - the name of the field

Returns:

the offset of that field within a record

recordLength

public int recordLength()

Returns the length of a record, in bytes.

Returns:

the length in bytes of a record