Class CsvAsyncWriter<T>

Namespace

FlameCsv

Assembly

FlameCsv.Core.dll

Instance that provides convenience methods around CsvFieldWriter<T>.

public class CsvAsyncWriter<T> : IAsyncDisposable where T : unmanaged, IBinaryInteger<T>

Type Parameters

T

Token type

Inheritance

object

CsvAsyncWriter<T>

Implements

IAsyncDisposable

Derived

CsvWriter<T>

Constructors

CsvAsyncWriter(CsvFieldWriter<T>, bool)

Initializes a new writer instance.

public CsvAsyncWriter(CsvFieldWriter<T> inner, bool autoFlush)

Parameters

inner CsvFieldWriter<T>

Field writer instance to write to

autoFlush bool

Whether to automatically flush after each record if the writer's buffer pressure is high enough. Automatic flushing is performed in NextRecord() and NextRecordAsync(CancellationToken).

Properties

AutoFlush

Whether to automatically check if the writer needs to be flushed after each record.

public bool AutoFlush { get; set; }

Property Value

bool

See Also

NeedsFlush

ColumnIndex

0-based index of the current column/field. Reset after each newline.

public int ColumnIndex { get; protected set; }

Property Value

int

ExpectedFieldCount

Field count required for each record, if set.

public int? ExpectedFieldCount { get; set; }

Property Value

int?

Remarks

Set automatically after the first non-empty record if ValidateFieldCount is true.

Inner

Inner field writer instance.

[EditorBrowsable(EditorBrowsableState.Advanced)]
protected CsvFieldWriter<T> Inner { get; }

Property Value

CsvFieldWriter<T>

IsCompleted

Whether the writer has completed (disposed).

public bool IsCompleted { get; }

Property Value

bool

LineIndex

1-based index of the current line/record. Incremented after each newline.

public int LineIndex { get; protected set; }

Property Value

int

Remarks

Newlines in quoted fields/strings are not counted, this property represents the logical CSV record index.

Options

Options instance of this writer.

public CsvOptions<T> Options { get; }

Property Value

CsvOptions<T>

Methods

CompleteAsync(Exception?, CancellationToken)

Completes the writer, flushing any remaining data if exception is null.
Multiple completions are no-ops.

public ValueTask CompleteAsync(Exception? exception = null, CancellationToken cancellationToken = default)

Parameters

exception Exception

Observed exception when writing the data, passed to the inner ICsvPipeWriter<T>. If not null, the final buffer is not flushed and the exception is rethrown.

cancellationToken CancellationToken

Token to cancel the operation

Returns

ValueTask

FlushAsync(CancellationToken)

Flushes the writer.

public ValueTask FlushAsync(CancellationToken cancellationToken = default)

Parameters

cancellationToken CancellationToken

Token to cancel flushing

Returns

ValueTask

Exceptions

ObjectDisposedException

Thrown if the writer has completed (see CompleteAsync(Exception?, CancellationToken)).

GetDematerializerAndIncrementFieldCount<TRecord>()

Returns or creates a cached dematerializer using TypeBinder, and pre-increments ColumnIndex by FieldCount.

[RequiresUnreferencedCode("This code path uses reflection. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
[RequiresDynamicCode("This code path uses compiled expressions. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
protected IDematerializer<T, TRecord> GetDematerializerAndIncrementFieldCount<TRecord>()

Returns

IDematerializer<T, TRecord>

Type Parameters

TRecord

Type to write

GetDematerializerAndIncrementFieldCount<TRecord>(CsvTypeMap<T, TRecord>)

Returns or creates a cached dematerializer using the type map, and pre-increments ColumnIndex by FieldCount.

protected IDematerializer<T, TRecord> GetDematerializerAndIncrementFieldCount<TRecord>(CsvTypeMap<T, TRecord> typeMap)

Parameters

typeMap CsvTypeMap<T, TRecord>

Type map instance

Returns

IDematerializer<T, TRecord>

Type Parameters

TRecord

Type to write

NextRecordAsync(CancellationToken)

Writes a newline and flushes the buffer if needed when AutoFlush is true.

public ValueTask NextRecordAsync(CancellationToken cancellationToken = default)

Parameters

cancellationToken CancellationToken

Token to cancel the flush

Returns

ValueTask

Exceptions

ObjectDisposedException

The writer has completed

ValidateFieldCount()

Validates the current record's field count if ValidateFieldCount is true. Called when moving to the next record.

protected void ValidateFieldCount()

WriteDelimiterIfNeeded()

Writes a delimiter if the current column index is not 0.

protected void WriteDelimiterIfNeeded()

WriteField(ReadOnlySpan<char>, bool)

Writes a field with the preceding delimiter if needed.

public void WriteField(ReadOnlySpan<char> text, bool skipEscaping = false)

Parameters

text ReadOnlySpan<char>

Value to write

skipEscaping bool

Whether no escaping should be performed, use with care

WriteField(ReadOnlySpan<T>, bool)

Writes a field with the preceding delimiter if needed.

public void WriteField(ReadOnlySpan<T> text, bool skipEscaping = false)

Parameters

text ReadOnlySpan<T>

Value to write

skipEscaping bool

Whether no escaping should be performed, use with care

WriteField<TField>(CsvConverter<T, TField>, TField?)

Writes a field with the preceding delimiter if needed.

public void WriteField<TField>(CsvConverter<T, TField> converter, TField? value)

Parameters

converter CsvConverter<T, TField>

Converter instance to write the value with

value TField

Value to write

Type Parameters

TField

Field type that will be converted

WriteField<TField>(TField?)

Writes a field with the preceding delimiter if needed.

[RequiresDynamicCode("This code path may require types that cannot be statically analyzed and might need runtime code generation. Use an alternative overload for native AOT applications.")]
[RequiresUnreferencedCode("This code path may require types that cannot be statically analyzed and might need runtime code generation. Use an alternative overload for native AOT applications.")]
public void WriteField<TField>(TField? value)

Parameters

value TField

Value to write

Type Parameters

TField

Field type that will be converted

Remarks

Converter will be retrieved from options.

WriteHeader<TRecord>()

Writes the header for TRecord to the current line using TypeBinder.

[RequiresUnreferencedCode("This code path uses reflection. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
[RequiresDynamicCode("This code path uses compiled expressions. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
public void WriteHeader<TRecord>()

Type Parameters

TRecord

Remarks

Does not write a trailing newline, see NextRecord() and NextRecordAsync(CancellationToken).

WriteHeader<TRecord>(CsvTypeMap<T, TRecord>)

Writes the header for TRecord to the current line using the type map.

public void WriteHeader<TRecord>(CsvTypeMap<T, TRecord> typeMap)

Parameters

typeMap CsvTypeMap<T, TRecord>

Type map to use for writing

Type Parameters

TRecord

Remarks

Does not write a trailing newline, see NextRecord() and NextRecordAsync(CancellationToken).

WriteRaw(ReadOnlySpan<T>, int, int)

Writes a sequence of raw characters to the writer. ColumnIndex and LineIndex are not tracked automatically, and no escaping is performed.

[EditorBrowsable(EditorBrowsableState.Advanced)]
public void WriteRaw(ReadOnlySpan<T> value, int columnsWritten = 0, int linesWritten = 0)

Parameters

value ReadOnlySpan<T>

Value to write

columnsWritten int

How many columns the value spans

linesWritten int

How many new lines the value spans

WriteRecord<TRecord>(CsvTypeMap<T, TRecord>, TRecord)

Writes the value to the current line using the type map.

public void WriteRecord<TRecord>(CsvTypeMap<T, TRecord> typeMap, TRecord value)

Parameters

typeMap CsvTypeMap<T, TRecord>

Type map to use for writing

value TRecord

Value to write

Type Parameters

TRecord

Remarks

Does not write a trailing newline, see NextRecord() and NextRecordAsync(CancellationToken).

WriteRecord<TRecord>(TRecord)

Writes the value to the current line using TypeBinder.

[RequiresUnreferencedCode("This code path uses reflection. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
[RequiresDynamicCode("This code path uses compiled expressions. Use the overloads accepting source generated CsvTypeMap for AOT/trimming compatible code.")]
public void WriteRecord<TRecord>(TRecord value)

Parameters

value TRecord

Value to write

Type Parameters

TRecord

Remarks

Does not write a trailing newline, see NextRecord() and NextRecordAsync(CancellationToken).