Fastpath (PostgreSQL JDBC Driver - JDBC 4.2 9.4.1212 API)

java.lang.Object
- org.postgresql.fastpath.Fastpath

```
public class Fastpath
extends Object
```
This class implements the Fastpath api.
This is a means of executing functions embedded in the backend from within a java application.
It is based around the file src/interfaces/libpq/fe-exec.c

Constructor Summary

Constructors
Constructor and Description

Fastpath(BaseConnection conn)
Initialises the fastpath system

Constructors
Constructor and Description
`Fastpath(BaseConnection conn)` Initialises the fastpath system

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`addFunction(String name, int fnid)` This adds a function to our lookup table.
`void`	`addFunctions(ResultSet rs)` This takes a ResultSet containing two columns.
`static FastpathArg`	`createOIDArg(long oid)` Creates a FastpathArg with an oid parameter.
`Object`	`fastpath(int fnId, boolean resultType, FastpathArg[] args)` Deprecated. please use `fastpath(int, FastpathArg[])`
`byte[]`	`fastpath(int fnId, FastpathArg[] args)` Send a function call to the PostgreSQL backend
`Object`	`fastpath(String name, boolean resulttype, FastpathArg[] args)` Deprecated. Use `getData(String, FastpathArg[])` if you expect a binary result, or one of `getInteger(String, FastpathArg[])` or `getLong(String, FastpathArg[])` if you expect a numeric one
`byte[]`	`fastpath(String name, FastpathArg[] args)` Send a function call to the PostgreSQL backend by name.
`byte[]`	`getData(String name, FastpathArg[] args)` This convenience method assumes that the return value is not an Integer
`int`	`getID(String name)` This returns the function id associated by its name.
`int`	`getInteger(String name, FastpathArg[] args)` This convenience method assumes that the return value is an integer
`long`	`getLong(String name, FastpathArg[] args)` This convenience method assumes that the return value is a long (bigint)
`long`	`getOID(String name, FastpathArg[] args)` This convenience method assumes that the return value is an oid.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Fastpath
```
public Fastpath(BaseConnection conn)
```
    Initialises the fastpath system
    
    Parameters:
    
    conn - BaseConnection to attach to
- Method Detail
  - fastpath
```
@Deprecated
public Object fastpath(int fnId,
                                   boolean resultType,
                                   FastpathArg[] args)
                            throws SQLException
```
    Deprecated. please use fastpath(int, FastpathArg[])
    
    Send a function call to the PostgreSQL backend
    
    Parameters:
    
    fnId - Function id
    
    resultType - True if the result is a numeric (Integer or Long)
    
    args - FastpathArguments to pass to fastpath
    
    Returns:
    
    null if no data, Integer if an integer result, Long if a long result, or byte[] otherwise
    
    Throws:
    
    SQLException - if a database-access error occurs.
  - fastpath
```
public byte[] fastpath(int fnId,
                       FastpathArg[] args)
                throws SQLException
```
    Send a function call to the PostgreSQL backend
    
    Parameters:
    
    fnId - Function id
    
    args - FastpathArguments to pass to fastpath
    
    Returns:
    
    null if no data, byte[] otherwise
    
    Throws:
    
    SQLException - if a database-access error occurs.
  - fastpath
```
@Deprecated
public Object fastpath(String name,
                                   boolean resulttype,
                                   FastpathArg[] args)
                            throws SQLException
```
    Deprecated. Use getData(String, FastpathArg[]) if you expect a binary result, or one of getInteger(String, FastpathArg[]) or getLong(String, FastpathArg[]) if you expect a numeric one
    
    Parameters:
    
    name - Function name
    
    resulttype - True if the result is a numeric (Integer or Long)
    
    args - FastpathArguments to pass to fastpath
    
    Returns:
    
    null if no data, Integer if an integer result, Long if a long result, or byte[] otherwise
    
    Throws:
    
    SQLException - if something goes wrong
    
    See Also:
    
    fastpath(int, FastpathArg[]), fastpath(String, FastpathArg[])
  - fastpath
```
public byte[] fastpath(String name,
                       FastpathArg[] args)
                throws SQLException
```
    Send a function call to the PostgreSQL backend by name. Note: the mapping for the procedure name to function id needs to exist, usually to an earlier call to addfunction(). This is the preferred method to call, as function id's can/may change between versions of the backend. For an example of how this works, refer to org.postgresql.largeobject.LargeObject
    
    Parameters:
    
    name - Function name
    
    args - FastpathArguments to pass to fastpath
    
    Returns:
    
    null if no data, byte[] otherwise
    
    Throws:
    
    SQLException - if name is unknown or if a database-access error occurs.
    
    See Also:
    
    LargeObject
  - getInteger
```
public int getInteger(String name,
                      FastpathArg[] args)
               throws SQLException
```
    This convenience method assumes that the return value is an integer
    
    Parameters:
    
    name - Function name
    
    args - Function arguments
    
    Returns:
    
    integer result
    
    Throws:
    
    SQLException - if a database-access error occurs or no result
  - getLong
```
public long getLong(String name,
                    FastpathArg[] args)
             throws SQLException
```
    This convenience method assumes that the return value is a long (bigint)
    
    Parameters:
    
    name - Function name
    
    args - Function arguments
    
    Returns:
    
    long result
    
    Throws:
    
    SQLException - if a database-access error occurs or no result
  - getOID
```
public long getOID(String name,
                   FastpathArg[] args)
            throws SQLException
```
    This convenience method assumes that the return value is an oid.
    
    Parameters:
    
    name - Function name
    
    args - Function arguments
    
    Returns:
    
    oid of the given call
    
    Throws:
    
    SQLException - if a database-access error occurs or no result
  - getData
```
public byte[] getData(String name,
                      FastpathArg[] args)
               throws SQLException
```
    This convenience method assumes that the return value is not an Integer
    
    Parameters:
    
    name - Function name
    
    args - Function arguments
    
    Returns:
    
    byte[] array containing result
    
    Throws:
    
    SQLException - if a database-access error occurs or no result
  - addFunction
```
public void addFunction(String name,
                        int fnid)
```
    This adds a function to our lookup table.
    User code should use the addFunctions method, which is based upon a query, rather than hard coding the oid. The oid for a function is not guaranteed to remain static, even on different servers of the same version.
    
    Parameters:
    
    name - Function name
    
    fnid - Function id
  - addFunctions
```
public void addFunctions(ResultSet rs)
                  throws SQLException
```
    This takes a ResultSet containing two columns. Column 1 contains the function name, Column 2 the oid.
    It reads the entire ResultSet, loading the values into the function table.
    REMEMBER to close() the resultset after calling this!!
    Implementation note about function name lookups:
    PostgreSQL stores the function id's and their corresponding names in the pg_proc table. To speed things up locally, instead of querying each function from that table when required, a HashMap is used. Also, only the function's required are entered into this table, keeping connection times as fast as possible.
    The org.postgresql.largeobject.LargeObject class performs a query upon it's startup, and passes the returned ResultSet to the addFunctions() method here.
    Once this has been done, the LargeObject api refers to the functions by name.
    Dont think that manually converting them to the oid's will work. Ok, they will for now, but they can change during development (there was some discussion about this for V7.0), so this is implemented to prevent any unwarranted headaches in the future.
    
    Parameters:
    
    rs - ResultSet
    
    Throws:
    
    SQLException - if a database-access error occurs.
    
    See Also:
    
    LargeObjectManager
  - getID
```
public int getID(String name)
          throws SQLException
```
    This returns the function id associated by its name.
    If addFunction() or addFunctions() have not been called for this name, then an SQLException is thrown.
    
    Parameters:
    
    name - Function name to lookup
    
    Returns:
    
    Function ID for fastpath call
    
    Throws:
    
    SQLException - is function is unknown.
  - createOIDArg
```
public static FastpathArg createOIDArg(long oid)
```
    Creates a FastpathArg with an oid parameter. This is here instead of a constructor of FastpathArg because the constructor can't tell the difference between an long that's really int8 and a long thats an oid.
    
    Parameters:
    
    oid - input oid
    
    Returns:
    
    FastpathArg with an oid parameter

Class Fastpath

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Fastpath

Method Detail

fastpath

fastpath

fastpath

fastpath

getInteger

getLong

getOID

getData

addFunction

addFunctions

getID

createOIDArg