DataStructures::Table Class Reference

Holds a set of columns, a set of rows, and rows times columns cells. More...

#include <DS_Table.h>

List of all members.

Classes

struct  Cell
 Holds the actual data in the table. More...
struct  ColumnDescriptor
struct  Row
 Stores the list of cells for this row, and a special flag used for internal sorting. More...

Public Types

enum  SortQueryType
 Increasing or decreasing sort order.

Public Member Functions

unsigned AddColumn (const char columnName[_TABLE_MAX_COLUMN_NAME_LENGTH], ColumnType columnType)
 Adds a column to the table.
void RemoveColumn (unsigned columnIndex)
 Removes a column by index.
unsigned ColumnIndex (char columnName[_TABLE_MAX_COLUMN_NAME_LENGTH]) const
 Gets the index of a column by name.
char * ColumnName (unsigned index) const
 Gives the string name of the column at a certain index.
ColumnType GetColumnType (unsigned index) const
 Returns the type of a column, referenced by index.
unsigned GetColumnCount (void) const
unsigned GetRowCount (void) const
Table::Row * AddRow (unsigned rowId)
 Adds a row to the table.
bool RemoveRow (unsigned rowId)
 Removes a row specified by rowId.
void RemoveRows (Table *tableContainingRowIDs)
 Removes all the rows with IDs that the specified table also has.
bool UpdateCell (unsigned rowId, unsigned columnIndex, int value)
 Updates a particular cell in the table.
void GetCellValueByIndex (unsigned rowIndex, unsigned columnIndex, int *output)
 Note this is much less efficient to call than GetRow, then working with the cells directly. Numeric, string, binary.
RowGetRowByID (unsigned rowId) const
 Gets a row. More efficient to do this and access Row::cells than to repeatedly call GetCell. You can also update cells in rows from this function.
RowGetRowByIndex (unsigned rowIndex, unsigned *key) const
 Gets a row at a specific index. rowIndex should be less than GetRowCount().
void QueryTable (unsigned *columnIndicesSubset, unsigned numColumnSubset, FilterQuery *inclusionFilters, unsigned numInclusionFilters, unsigned *rowIds, unsigned numRowIDs, Table *result)
 Queries the table, optionally returning only a subset of columns and rows.
void SortTable (Table::SortQuery *sortQueries, unsigned numSortQueries, Table::Row **out)
 Sorts the table by rows.
void Clear (void)
 Frees all memory in the table.
void PrintColumnHeaders (char *out, int outLength, char columnDelineator) const
 Prints out the names of all the columns.
void PrintRow (char *out, int outLength, char columnDelineator, bool printDelineatorForBinary, Table::Row *inputRow) const
 Writes a text representation of the row to out.
const DataStructures::List
< ColumnDescriptor > & 
GetColumns (void) const
 Direct access to make things easier.
const
DataStructures::BPlusTree
< unsigned, Row
*, _TABLE_BPLUS_TREE_ORDER > & 
GetRows (void) const
 Direct access to make things easier.
DataStructures::Page< unsigned,
Row *, _TABLE_BPLUS_TREE_ORDER > * 
GetListHead (void)
 Get the head of a linked list containing all the row data.
unsigned GetAvailableRowId (void) const
 Get the first free row id. This could be made more efficient.


Detailed Description

Holds a set of columns, a set of rows, and rows times columns cells.

The table data structure is useful if you want to store a set of structures and perform queries on those structures.
This is a relatively simple and fast implementation of the types of tables commonly used in databases.
See TableSerializer to serialize data members of the table.
See LightweightDatabaseClient and LightweightDatabaseServer to transmit the table over the network.


Member Function Documentation

unsigned DataStructures::Table::AddColumn ( const char  columnName[_TABLE_MAX_COLUMN_NAME_LENGTH],
ColumnType  columnType 
)

Adds a column to the table.

Parameters:
[in] columnName The name of the column
[in] columnType What type of data this column will hold
Returns:
The index of the new column

Table::Row* DataStructures::Table::AddRow ( unsigned  rowId  ) 

Adds a row to the table.

New rows are added with empty values for all cells. However, if you specify initialCelLValues you can specify initial values It's up to you to ensure that the values in the specific cells match the type of data used by that row rowId can be considered the primary key for the row. It is much faster to lookup a row by its rowId than by searching keys. rowId must be unique Rows are stored in sorted order in the table, using rowId as the sort key

Parameters:
[in] rowId The UNIQUE primary key for the row. This can never be changed.
[in] initialCellValues Initial values to give the row (optional)
Returns:
The newly added row

unsigned DataStructures::Table::ColumnIndex ( char  columnName[_TABLE_MAX_COLUMN_NAME_LENGTH]  )  const

Gets the index of a column by name.

Column indices are stored in the order they are added.

Parameters:
[in] columnName The name of the column
Returns:
The index of the column, or (unsigned)-1 if no such column

char* DataStructures::Table::ColumnName ( unsigned  index  )  const

Gives the string name of the column at a certain index.

Parameters:
[in] index The index of the column
Returns:
The name of the column, or 0 if an invalid index

unsigned DataStructures::Table::GetColumnCount ( void   )  const

Returns the number of columns

Returns:
The number of columns in the table

ColumnType DataStructures::Table::GetColumnType ( unsigned  index  )  const

Returns the type of a column, referenced by index.

Parameters:
[in] index The index of the column
Returns:
The type of the column

Row* DataStructures::Table::GetRowByID ( unsigned  rowId  )  const

Gets a row. More efficient to do this and access Row::cells than to repeatedly call GetCell. You can also update cells in rows from this function.

Parameters:
[in] rowId The ID of the row
Returns:
The desired row, or 0 if no such row.

Row* DataStructures::Table::GetRowByIndex ( unsigned  rowIndex,
unsigned *  key 
) const

Gets a row at a specific index. rowIndex should be less than GetRowCount().

Parameters:
[in] rowIndex The index of the row
[out] key The ID of the row returned
Returns:
The desired row, or 0 if no such row.

unsigned DataStructures::Table::GetRowCount ( void   )  const

Returns the number of rows

Returns:
The number of rows in the table

void DataStructures::Table::PrintColumnHeaders ( char *  out,
int  outLength,
char  columnDelineator 
) const

Prints out the names of all the columns.

Parameters:
[out] out A pointer to an array of bytes which will hold the output.
[in] outLength The size of the out array
[in] columnDelineator What character to print to delineate columns

void DataStructures::Table::PrintRow ( char *  out,
int  outLength,
char  columnDelineator,
bool  printDelineatorForBinary,
Table::Row *  inputRow 
) const

Writes a text representation of the row to out.

Parameters:
[out] out A pointer to an array of bytes which will hold the output.
[in] outLength The size of the out array
[in] columnDelineator What character to print to delineate columns
[in] printDelineatorForBinary Binary output is not printed. True to still print the delineator.
[in] inputRow The row to print

void DataStructures::Table::QueryTable ( unsigned *  columnIndicesSubset,
unsigned  numColumnSubset,
FilterQuery *  inclusionFilters,
unsigned  numInclusionFilters,
unsigned *  rowIds,
unsigned  numRowIDs,
Table result 
)

Queries the table, optionally returning only a subset of columns and rows.

Parameters:
[in] columnSubset An array of column indices. Only columns in this array are returned. Pass 0 for all columns
[in] numColumnSubset The number of elements in columnSubset
[in] inclusionFilters An array of FilterQuery. All filters must pass for the row to be returned.
[in] numInclusionFilters The number of elements in inclusionFilters
[in] rowIds An arrow of row IDs. Only these rows with these IDs are returned. Pass 0 for all rows.
[in] numRowIDs The number of elements in rowIds
[out] result The result of the query. If no rows are returned, the table will only have columns.

void DataStructures::Table::RemoveColumn ( unsigned  columnIndex  ) 

Removes a column by index.

Parameters:
[in] columnIndex The index of the column to remove

bool DataStructures::Table::RemoveRow ( unsigned  rowId  ) 

Removes a row specified by rowId.

Parameters:
[in] rowId The ID of the row
Returns:
true if the row was deleted. False if not.

void DataStructures::Table::RemoveRows ( Table tableContainingRowIDs  ) 

Removes all the rows with IDs that the specified table also has.

Parameters:
[in] tableContainingRowIDs The IDs of the rows

void DataStructures::Table::SortTable ( Table::SortQuery *  sortQueries,
unsigned  numSortQueries,
Table::Row **  out 
)

Sorts the table by rows.

You can sort the table in ascending or descending order on one or more columns Columns have precedence in the order they appear in the sortQueries array If a row cell on column n has the same value as a a different row on column n, then the row will be compared on column n+1

Parameters:
[in] sortQueries A list of SortQuery structures, defining the sorts to perform on the table
[in] numColumnSubset The number of elements in numSortQueries
[out] out The address of an array of Rows, which will receive the sorted output. The array must be long enough to contain all returned rows, up to GetRowCount()

bool DataStructures::Table::UpdateCell ( unsigned  rowId,
unsigned  columnIndex,
int  value 
)

Updates a particular cell in the table.

Note:
If you are going to update many cells of a particular row, it is more efficient to call GetRow and perform the operations on the row directly.

Row pointers do not change, so you can also write directly to the rows for more efficiency.

Parameters:
[in] rowId The ID of the row
[in] columnIndex The column of the cell
[in] value The data to set


The documentation for this class was generated from the following file:

Generated on Wed Feb 1 13:33:47 2012 for RakNet by  doxygen 1.5.7.1