protocol Directory Reference

Directory dependency graph for protocol:

Directories
	detail

Files
	AccountID.h
	AMMCore.h
	AmountConversions.h
	ApiVersion.h
	Asset.h
	Batch.h
	Book.h
	BuildInfo.h
	Concepts.h
	ConfidentialTransfer.h
	digest.h
	ErrorCodes.h
	Feature.h
	Fees.h
	HashPrefix.h
	Indexes.h
	InnerObjectFormats.h
	IOUAmount.h
	Issue.h
	json_get_or_throw.h
	jss.h
	Keylet.h
	KeyType.h
	KnownFormats.h
	LedgerFormats.h
	LedgerHeader.h
	LedgerShortcut.h
	messages.h
	MPTAmount.h
	MPTIssue.h
	MultiApiJson.h
	nft.h
	NFTokenID.h
	NFTokenOfferID.h
	nftPageMask.h
	NFTSyntheticSerializer.h
	PathAsset.h
	PayChan.h
	Permissions.h
	Protocol.h
	PublicKey.h
	Quality.h
	QualityFunction.h
	Rate.h
	RippleLedgerHash.h
	RPCErr.h
	Rules.h
	SecretKey.h
	Seed.h
	SeqProxy.h
	serialize.h
	Serializer.h
	SField.h
	Sign.h
	SOTemplate.h
	st.h
	STAccount.h
	STAmount.h
	STArray.h
	STBase.h
	STBitString.h
	STBlob.h
	STCurrency.h
	STExchange.h
	STInteger.h
	STIssue.h
	STLedgerEntry.h
	STNumber.h
	STObject.h
	STParsedJSON.h
	STPathSet.h
	STTakesAsset.h
	STTx.h
	STValidation.h
	STVector256.h
	STXChainBridge.h
	SystemParameters.h
	TER.h
	tokens.h
	TxFlags.h
	TxFormats.h
	TxMeta.h
	TxSearched.h
	UintTypes.h
	Units.h
	XChainAttestations.h
	XRPAmount.h

Detailed Description

protocol

Classes and functions for handling data and values associated with the XRP Ledger protocol.

Serialized Objects

Objects transmitted over the network must be serialized into a canonical format. The prefix "ST" refers to classes that deal with the serialized format.

The term "Tx" or "tx" is an abbreviation for "Transaction", a commonly occurring object type.

Optional Fields

Our serialized fields have some "type magic" to make optional fields easier to read:

• The operation x[sfFoo] means "return the value of 'Foo' if it exists, or the default value if it doesn't."
• The operation x[~sfFoo] means "return the value of 'Foo' if it exists, or nothing if it doesn't." This usage of the tilde/bitwise NOT operator is not standard outside of the xrpld codebase.
  • As a consequence of this, x[~sfFoo] = y[~sfFoo] assigns the value of Foo from y to x, including omitting Foo from x if it doesn't exist in y.

Typically, for things that are guaranteed to exist, you use x[sfFoo] and avoid having to deal with a container that may or may not hold a value. For things not guaranteed to exist, you use x[~sfFoo] because you want such a container. It avoids having to look something up twice, once just to see if it exists and a second time to get/set its value. (Real example)

The source of this "type magic" is in SField.h.

Related Resources

• ripple-binary-codec SField enums
• SFCode Registry Tables