rabosh-variant/app.oreshkov.rabosh.variant/VariantBuilder

VariantBuilder

class VariantBuilder(val dictionary: VariantDictionaryBuilder = VariantDictionaryBuilder(), duplicateFields: DuplicateFieldPolicy = DuplicateFieldPolicy.LAST_WINS)

Encodes Variant values.

The builder is a streaming encoder: values are appended to one growable buffer in the order they arrive, and a container's header — which cannot be written first, because it depends on how many elements there turn out to be, how wide their offsets are and how large the biggest field id is — is inserted in front of the children once they are complete. That keeps encoding to a single pass with no intermediate tree.

val builder = VariantBuilder()
builder.startObject()
builder.field("id"); builder.appendLong(7)
builder.field("tags"); builder.startArray(); builder.appendString("a"); builder.endArray()
builder.endObject()
val variant = builder.buildVariant()

The dictionary is deliberately a constructor parameter rather than private state: an SSTable shares one dictionary across every document it holds, so the usual ingest loop creates the dictionary once, then resets the builder per document.

Not thread-safe; the engine has a single writer.

Constructors

constructor(dictionary: VariantDictionaryBuilder = VariantDictionaryBuilder(), duplicateFields: DuplicateFieldPolicy = DuplicateFieldPolicy.LAST_WINS)

Properties

val dictionary: VariantDictionaryBuilder

Field-name dictionary. Share one across a segment to pay for each name once.

Number of value bytes written so far.

Functions

fun append(value: Variant)

Appends value, re-expressed against this builder's dictionary.

fun appendBinary(value: ByteArray)

fun appendBoolean(value: Boolean)

fun appendDate(epochDay: Int)

Appends a date as days since 1970-01-01.

fun appendDecimal(value: BigDecimal)

Appends value as the narrowest exact decimal type.

fun appendDouble(value: Double)

Appends value as a double, non-finite values included; JSON cannot read those back.

fun appendFloat(value: Float)

fun appendLong(value: Long)

Appends value as the narrowest integer type that holds it.

fun appendNull()

Appends the Variant null primitive.

appendNumberLiteral

fun appendNumberLiteral(literal: String)

Appends a JSON number literal, choosing its physical type by the rule exact if possible, narrowest if exact:

fun appendString(value: String)

Appends value, using the short-string form when its UTF-8 form is under 64 bytes.

fun appendTimeNtz(microsOfDay: Long)

Appends a time without time zone as microseconds since midnight.

appendTimestampMicros

fun appendTimestampMicros(micros: Long, adjustedToUtc: Boolean)

Appends a timestamp in microseconds since the epoch.

appendTimestampNanos

fun appendTimestampNanos(nanos: Long, adjustedToUtc: Boolean)

Appends a timestamp in nanoseconds since the epoch. See appendTimestampMicros.

fun appendUuid(value: Uuid)

fun build(): ByteArray

The encoded value bytes. The builder may be reset and reused afterwards.

fun buildVariant(): Variant

The encoded value together with a snapshot of the dictionary.

Closes the array opened by the matching startArray.

fun endObject()

Closes the object opened by the matching startObject.

fun field(name: String)

Names the next value's field.

fun reset()

Discards the value under construction, keeping the dictionary for the next document.

fun startArray()

Opens an array.

fun startObject()

Opens an object. Every field must be followed by exactly one value.