Class RangeHandler<TElement>
A type handler for PostgreSQL range types.
Implements
Inherited Members
Namespace: Npgsql.TypeHandlers
Assembly: Npgsql.dll
Syntax
public class RangeHandler<TElement> : RangeHandler, INpgsqlTypeHandler<NpgsqlRange<TElement>>
Type Parameters
Name | Description |
---|---|
TElement | the range subtype |
Remarks
See http://www.postgresql.org/docs/current/static/rangetypes.html.
The type handler API allows customizing Npgsql's behavior in powerful ways. However, although it is public, it should be considered somewhat unstable, and may change in breaking ways, including in non-major releases. Use it at your own risk.
Constructors
RangeHandler(PostgresType, NpgsqlTypeHandler)
Declaration
public RangeHandler(PostgresType rangePostgresType, NpgsqlTypeHandler elementHandler)
Parameters
Type | Name | Description |
---|---|---|
PostgresType | rangePostgresType | |
NpgsqlTypeHandler | elementHandler |
Methods
CreateArrayHandler(PostgresArrayType)
Creates a type handler for arrays of this handler's type.
Declaration
public override ArrayHandler CreateArrayHandler(PostgresArrayType arrayBackendType)
Parameters
Type | Name | Description |
---|---|---|
PostgresArrayType | arrayBackendType |
Returns
Type | Description |
---|---|
ArrayHandler |
Overrides
Read(NpgsqlReadBuffer, Int32, Boolean, FieldDescription)
Reads a value of type T
with the given length from the provided buffer,
using either sync or async I/O.
Declaration
public ValueTask<NpgsqlRange<TElement>> Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription fieldDescription = null)
Parameters
Type | Name | Description |
---|---|---|
NpgsqlReadBuffer | buf | The buffer from which to read. |
System.Int32 | len | The byte length of the value. The buffer might not contain the full length, requiring I/O to be performed. |
System.Boolean | async | If I/O is required to read the full length of the value, whether it should be performed synchronously or asynchronously. |
FieldDescription | fieldDescription | Additional PostgreSQL information about the type, such as the length in varchar(30). |
Returns
Type | Description |
---|---|
ValueTask<NpgsqlRange<TElement>> | The fully-read value. |
Read<TAny>(NpgsqlReadBuffer, Int32, FieldDescription)
Reads a value of type TAny
with the given length from the provided buffer,
with the assumption that it is entirely present in the provided memory buffer and no I/O will be
required. This can save the overhead of async functions and improves performance.
Declaration
public override TAny Read<TAny>(NpgsqlReadBuffer buf, int len, FieldDescription fieldDescription = null)
Parameters
Type | Name | Description |
---|---|---|
NpgsqlReadBuffer | buf | The buffer from which to read. |
System.Int32 | len | The byte length of the value. The buffer might not contain the full length, requiring I/O to be performed. |
FieldDescription | fieldDescription | Additional PostgreSQL information about the type, such as the length in varchar(30). |
Returns
Type | Description |
---|---|
TAny | The fully-read value. |
Type Parameters
Name | Description |
---|---|
TAny |
Overrides
Read<TAny>(NpgsqlReadBuffer, Int32, Boolean, FieldDescription)
Reads a value of type TAny
with the given length from the provided buffer,
using either sync or async I/O.
Declaration
protected override ValueTask<TAny> Read<TAny>(NpgsqlReadBuffer buf, int len, bool async, FieldDescription fieldDescription = null)
Parameters
Type | Name | Description |
---|---|---|
NpgsqlReadBuffer | buf | The buffer from which to read. |
System.Int32 | len | The byte length of the value. The buffer might not contain the full length, requiring I/O to be performed. |
System.Boolean | async | If I/O is required to read the full length of the value, whether it should be performed synchronously or asynchronously. |
FieldDescription | fieldDescription | Additional PostgreSQL information about the type, such as the length in varchar(30). |
Returns
Type | Description |
---|---|
ValueTask<TAny> | The fully-read value. |
Type Parameters
Name | Description |
---|---|
TAny |
Overrides
ValidateAndGetLength(NpgsqlRange<TElement>, ref NpgsqlLengthCache, NpgsqlParameter)
Responsible for validating that a value represents a value of the correct and which can be written for PostgreSQL - if the value cannot be written for any reason, an exception should be thrown. Also returns the byte length needed to write the value.
Declaration
public int ValidateAndGetLength(NpgsqlRange<TElement> value, ref NpgsqlLengthCache lengthCache, NpgsqlParameter parameter)
Parameters
Type | Name | Description |
---|---|---|
NpgsqlRange<TElement> | value | |
NpgsqlLengthCache | lengthCache | A cache where the length calculated during the validation phase can be stored for use at the writing phase. |
NpgsqlParameter | parameter | The NpgsqlParameter instance where this value resides. Can be used to access additional information relevant to the write process (e.g. Size). |
Returns
Type | Description |
---|---|
System.Int32 | The number of bytes required to write the value. |
ValidateAndGetLength<TAny>(TAny, ref NpgsqlLengthCache, NpgsqlParameter)
Called to validate and get the length of a value of a generic NpgsqlParameter<T>.
Declaration
protected override int ValidateAndGetLength<TAny>(TAny value, ref NpgsqlLengthCache lengthCache, NpgsqlParameter parameter)
Parameters
Type | Name | Description |
---|---|---|
TAny | value | |
NpgsqlLengthCache | lengthCache | |
NpgsqlParameter | parameter |
Returns
Type | Description |
---|---|
System.Int32 |
Type Parameters
Name | Description |
---|---|
TAny |
Overrides
ValidateObjectAndGetLength(Object, ref NpgsqlLengthCache, NpgsqlParameter)
Responsible for validating that a value represents a value of the correct and which can be written for PostgreSQL - if the value cannot be written for any reason, an exception shold be thrown. Also returns the byte length needed to write the value.
Declaration
protected override int ValidateObjectAndGetLength(object value, ref NpgsqlLengthCache lengthCache, NpgsqlParameter parameter)
Parameters
Type | Name | Description |
---|---|---|
System.Object | value | The value to be written to PostgreSQL |
NpgsqlLengthCache | lengthCache | If the byte length calculation is costly (e.g. for UTF-8 strings), its result can be stored in the length cache to be reused in the writing process, preventing recalculation. |
NpgsqlParameter | parameter | The NpgsqlParameter instance where this value resides. Can be used to access additional information relevant to the write process (e.g. Size). |
Returns
Type | Description |
---|---|
System.Int32 | The number of bytes required to write the value. |
Overrides
Write(NpgsqlRange<TElement>, NpgsqlWriteBuffer, NpgsqlLengthCache, NpgsqlParameter, Boolean)
Writes a value to the provided buffer.
Declaration
public Task Write(NpgsqlRange<TElement> value, NpgsqlWriteBuffer buf, NpgsqlLengthCache lengthCache, NpgsqlParameter parameter, bool async)
Parameters
Type | Name | Description |
---|---|---|
NpgsqlRange<TElement> | value | |
NpgsqlWriteBuffer | buf | The buffer to which to write. |
NpgsqlLengthCache | lengthCache | A cache where the length calculated during the validation phase can be stored for use at the writing phase. |
NpgsqlParameter | parameter | The NpgsqlParameter instance where this value resides. Can be used to access additional information relevant to the write process (e.g. Size). |
System.Boolean | async | If I/O will be necessary (i.e. the buffer is full), determines whether it will be done synchronously or asynchronously. |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task |
WriteObjectWithLength(Object, NpgsqlWriteBuffer, NpgsqlLengthCache, NpgsqlParameter, Boolean)
Writes a value to the provided buffer, using either sync or async I/O.
Declaration
protected override Task WriteObjectWithLength(object value, NpgsqlWriteBuffer buf, NpgsqlLengthCache lengthCache, NpgsqlParameter parameter, bool async)
Parameters
Type | Name | Description |
---|---|---|
System.Object | value | The value to write. |
NpgsqlWriteBuffer | buf | The buffer to which to write. |
NpgsqlLengthCache | lengthCache | |
NpgsqlParameter | parameter | The NpgsqlParameter instance where this value resides. Can be used to access additional information relevant to the write process (e.g. Size). |
System.Boolean | async | If I/O is required to read the full length of the value, whether it should be performed synchronously or asynchronously. |
Returns
Type | Description |
---|---|
System.Threading.Tasks.Task |