cs

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 Go to latest Published: May 4, 2023 License: GPL-3.0 Imports: 19 Imported by: 0

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Index

Constants

View Source 
const (
	CoeffIdZero = iota
	CoeffIdOne
	CoeffIdTwo
	CoeffIdMinusOne
	CoeffIdMinusTwo
)

ids of the coefficients with simple values in any cs.coeffs slice.

View Source 
const CommitmentDst = "bsb22-commitment"
View Source 
const ConstrainSystemTypeR1CS = 1

Variables

This section is empty.

Functions

func FromInterface 

func FromInterface(input interface{}) big.Int

FromInterface converts an interface to a big.Int element

input must be primitive (uintXX, intXX, []byte, string) or implement BigInt(res *big.Int) (which is the case for gnark-crypto field elements)

if the input is a string, it calls (big.Int).SetString(input, 0). In particular: The number prefix determines the actual base: A prefix of ”0b” or ”0B” selects base 2, ”0”, ”0o” or ”0O” selects base 8, and ”0x” or ”0X” selects base 16. Otherwise, the selected base is 10 and no prefix is accepted.

panics if the input is invalid

Types

type Blueprint 

type Blueprint interface {
	// NbInputs return the number of calldata input this blueprint expects.
	// If this is unknown at compile time, implementation must return -1 and store
	// the actual number of inputs in the first index of the calldata.
	NbInputs() int

	// NbConstraints return the number of constraints this blueprint creates.
	NbConstraints() int
}

Blueprint enable representing heterogenous constraints or instructions in a constraint system in a memory efficient way. Blueprints essentially help the frontend/ to "compress" constraints or instructions, and specify for the solving (or zksnark setup) part how to "decompress" and optionally "solve" the associated wires.

type BlueprintGenericHint 

type BlueprintGenericHint struct{}

func (*BlueprintGenericHint) CompressHint 

func (b *BlueprintGenericHint) CompressHint(h HintMapping) []uint32

func (*BlueprintGenericHint) DecompressHint 

func (b *BlueprintGenericHint) DecompressHint(h *HintMapping, calldata []uint32)

func (*BlueprintGenericHint) NbConstraints 

func (b *BlueprintGenericHint) NbConstraints() int

func (*BlueprintGenericHint) NbInputs 

func (b *BlueprintGenericHint) NbInputs() int

type BlueprintGenericR1C 

type BlueprintGenericR1C struct{}

BlueprintGenericR1C implements Blueprint and BlueprintR1C. Encodes 

L * R == 0

func (*BlueprintGenericR1C) CompressR1C 

func (b *BlueprintGenericR1C) CompressR1C(c *R1C) []uint32

func (*BlueprintGenericR1C) DecompressR1C 

func (b *BlueprintGenericR1C) DecompressR1C(c *R1C, calldata []uint32)

func (*BlueprintGenericR1C) NbConstraints 

func (b *BlueprintGenericR1C) NbConstraints() int

func (*BlueprintGenericR1C) NbInputs 

func (b *BlueprintGenericR1C) NbInputs() int

type BlueprintHint 

type BlueprintHint interface {
	CompressHint(HintMapping) []uint32
	DecompressHint(h *HintMapping, calldata []uint32)
}

BlueprintHint indicates that the blueprint and associated calldata encodes a hint.

type BlueprintID 

type BlueprintID uint32

type BlueprintR1C 

type BlueprintR1C interface {
	CompressR1C(c *R1C) []uint32
	DecompressR1C(into *R1C, calldata []uint32)
}

BlueprintR1C indicates that the blueprint and associated calldata encodes a R1C

type BlueprintSolvable 

type BlueprintSolvable interface {
	// Solve may return an error if the decoded constraint / calldata is unsolvable.
	Solve(s Solver, calldata []uint32) error
}

BlueprintSolvable represents a blueprint that knows how to solve itself.

type CoeffTable 

type CoeffTable struct {
	Coefficients []fr.Element
	// contains filtered or unexported fields
}

CoeffTable ensure we store unique coefficients in the constraint system

func (*CoeffTable) AddCoeff 

func (ct *CoeffTable) AddCoeff(coeff Element) uint32

func (*CoeffTable) CoeffToString 

func (ct *CoeffTable) CoeffToString(cID int) string

CoeffToString implements constraint.Resolver

func (*CoeffTable) MakeTerm 

func (ct *CoeffTable) MakeTerm(coeff Element, variableID int) Term

type Commitment 

type Commitment struct {
	Committed              []int // sorted list of id's of committed variables in groth16. in plonk, list of indexes of constraints defining committed values
	NbPrivateCommitted     int
	HintID                 hintsolver.HintID // TODO @gbotrel we probably don't need that here
	CommitmentIndex        int               // in groth16, CommitmentIndex is the wire index. in plonk, it's the constraint defining it
	CommittedAndCommitment []int             // sorted list of id's of committed variables AND the commitment itself
}

func NewCommitment 

func NewCommitment(committed []int, nbPublicCommitted int) Commitment

NewCommitment initialize a Commitment object

  • committed are the sorted wireID to commit to (without duplicate)
  • nbPublicCommited is the number of public inputs among the commited wireIDs

func (*Commitment) Is 

func (i *Commitment) Is() bool

func (*Commitment) NbCommitted 

func (i *Commitment) NbCommitted() int

func (*Commitment) NbPublicCommitted 

func (i *Commitment) NbPublicCommitted() int

func (*Commitment) PrivateCommitted 

func (i *Commitment) PrivateCommitted() []int

func (*Commitment) PrivateToPublic 

func (i *Commitment) PrivateToPublic() []int

PrivateToPublic returns indexes of variables which are private to the constraint system, but public to Groth16. That is, private committed variables and the commitment itself

func (*Commitment) SerializeCommitment 

func (i *Commitment) SerializeCommitment(privateCommitment []byte, publicCommitted []*big.Int, fieldByteLen int) []byte

type Element 

type Element [6]uint64

Element represents a term coefficient data. It is instantiated by the concrete constraint system implementation. Most of the scalar field used in gnark are on 4 uint64, so we have a clear memory overhead here.

func (*Element) IsZero 

func (z *Element) IsZero() bool

IsZero returns true if coefficient == 0

type Field 

type Field interface {
	FromInterface(interface{}) Element
	ToBigInt(Element) *big.Int
	Mul(a, b Element) Element
	Add(a, b Element) Element
	Sub(a, b Element) Element
	Neg(a Element) Element
	Inverse(a Element) (Element, bool)
	One() Element
	IsOne(Element) bool
	String(Element) string
}

Field capability to perform arithmetic on Coeff

type HintMapping 

type HintMapping struct {
	HintID      csolver.HintID     // Hint function id
	Inputs      []LinearExpression // Terms to inject in the hint function
	OutputRange struct {
		Start, End uint32
	}
}

HintMapping mark a list of output variables to be computed using provided hint and inputs.

func (*HintMapping) WireIterator 

func (h *HintMapping) WireIterator() func() int

WireIterator implements constraint.Iterable returns all the wires referenced by the hint.

type Instruction 

type Instruction struct {
	// BlueprintID maps this instruction to a blueprint
	BlueprintID BlueprintID

	// ConstraintOffset stores the starting constraint ID of this instruction.
	// Might not be strictly necessary; but speeds up solver for instructions that represents
	// multiple constraints.
	ConstraintOffset uint32

	// The constraint system stores a single []uint32 calldata slice. StartCallData
	// points to the starting index in the mentioned slice. This avoid storing a slice per
	// instruction (3 * uint64 in memory).
	StartCallData uint64
}

Instruction is the lowest element of a constraint system. It stores just enough data to reconstruct a constraint of any shape or a hint at solving time.

type LinearExpression 

type LinearExpression []Term

A LinearExpression is a linear combination of Term

func (LinearExpression) Clone 

func (l LinearExpression) Clone() LinearExpression

Clone returns a copy of the underlying slice

func (LinearExpression) String 

func (l LinearExpression) String(r Resolver) string

type R1C 

type R1C struct {
	L, R, O LinearExpression
}

R1C used to compute the wires

func (*R1C) String 

func (r1c *R1C) String(r Resolver) string

String formats a R1C as L⋅R == O

func (*R1C) WireIterator 

func (r1c *R1C) WireIterator() func() int

WireIterator implements constraint.Iterable

type R1CS 

type R1CS = system

func NewR1CS 

func NewR1CS(capacity int) *R1CS

type R1CSSolution 

type R1CSSolution struct {
	W       fr.Vector
	A, B, C fr.Vector
}

R1CSSolution represent a valid assignment to all the variables in the constraint system. The vector W such that Aw o Bw - Cw = 0

func (*R1CSSolution) ReadFrom 

func (t *R1CSSolution) ReadFrom(r io.Reader) (int64, error)

func (*R1CSSolution) WriteTo 

func (t *R1CSSolution) WriteTo(w io.Writer) (int64, error)

type ReaderCounter 

type ReaderCounter struct {
	R io.Reader
	N int64
}

func (*ReaderCounter) Read 

func (cr *ReaderCounter) Read(p []byte) (int, error)

type Resolver 

type Resolver interface {
	CoeffToString(coeffID int) string
	VariableToString(variableID int) string
}

Resolver allows pretty printing of constraints.

type Solver 

type Solver interface {
	Field
	GetValue(cID, vID uint32) Element
	GetCoeff(cID uint32) Element
	SetValue(vID uint32, f Element)
	IsSolved(vID uint32) bool
}

Solver represents the state of a constraint system solver at runtime. Blueprint can interact with this object to perform run time logic, solve constraints and assign values in the solution.

type StringBuilder 

type StringBuilder struct {
	strings.Builder
	Resolver
}

StringBuilder is a helper to build string from constraints, linear expressions or terms. It embeds a strings.Builder object for convenience.

func NewStringBuilder 

func NewStringBuilder(r Resolver) *StringBuilder

NewStringBuilder returns a new StringBuilder.

func (*StringBuilder) WriteLinearExpression 

func (sbb *StringBuilder) WriteLinearExpression(l LinearExpression)

WriteLinearExpression appends the linear expression to the current buffer

func (*StringBuilder) WriteTerm 

func (sbb *StringBuilder) WriteTerm(t Term)

WriteLinearExpression appends the term to the current buffer

type System 

type System struct {
	// serialization header
	ScalarField string

	Type int

	Instructions []Instruction
	Blueprints   []Blueprint
	CallData     []uint32 // huge slice.

	// can be != than len(instructions)
	NbConstraints int

	// number of internal wires
	NbInternalVariables int

	// input wires names
	Public, Secret []string

	// maps hintID to hint string identifier
	MHintsDependencies map[hintsolver.HintID]string

	// each level contains independent constraints and can be parallelized
	// it is guaranteed that all dependencies for constraints in a level l are solved
	// in previous levels
	// TODO @gbotrel these are currently updated after we add a constraint.
	// but in case the object is built from a serialized representation
	// we need to init the level builder lbWireLevel from the existing constraints.
	Levels [][]int

	CommitmentInfo Commitment
	// contains filtered or unexported fields
}

System contains core elements for a constraint System

func NewSystem 

func NewSystem(scalarField *big.Int, capacity int, t int) System

NewSystem initialize the common structure among constraint system

func (*System) AddBlueprint 

func (system *System) AddBlueprint(b Blueprint) BlueprintID

func (*System) AddCommitment 

func (system *System) AddCommitment(c Commitment) error

func (*System) AddInternalVariable 

func (system *System) AddInternalVariable() (idx int)

func (*System) AddPublicVariable 

func (system *System) AddPublicVariable(name string) (idx int)

func (*System) AddSecretVariable 

func (system *System) AddSecretVariable(name string) (idx int)

func (*System) CheckSerializationHeader 

func (system *System) CheckSerializationHeader() error

CheckSerializationHeader parses the scalar field and gnark version headers

This is meant to be use at the deserialization step, and will error for illegal values

func (*System) CheckUnconstrainedWires 

func (cs *System) CheckUnconstrainedWires() error

func (*System) Field 

func (system *System) Field() *big.Int

func (*System) FieldBitLen 

func (system *System) FieldBitLen() int

bitLen returns the number of bits needed to represent a fr.Element

func (*System) GetCallData 

func (cs *System) GetCallData(instruction Instruction) []uint32

GetCallData re-slice the constraint system full calldata slice with the portion related to the instruction. This does not copy and caller should not modify.

func (*System) GetInstruction 

func (system *System) GetInstruction(id int) Instruction

func (*System) GetNbConstraints 

func (cs *System) GetNbConstraints() int

GetNbConstraints returns the number of constraints

func (*System) GetNbInstructions 

func (system *System) GetNbInstructions() int

func (*System) GetNbInternalVariables 

func (system *System) GetNbInternalVariables() int

func (*System) GetNbPublicVariables 

func (system *System) GetNbPublicVariables() int

func (*System) GetNbSecretVariables 

func (system *System) GetNbSecretVariables() int

func (*System) GetNbVariables 

func (system *System) GetNbVariables() (internal, secret, public int)

GetNbVariables return number of internal, secret and public variables

func (*System) VariableToString 

func (system *System) VariableToString(vID int) string

VariableToString implements Resolver

type Term 

type Term struct {
	CID, VID uint32
}

Term represents a coeff * variable in a constraint system

func (*Term) CoeffID 

func (t *Term) CoeffID() int

func (*Term) IsConstant 

func (t *Term) IsConstant() bool

func (*Term) MarkConstant 

func (t *Term) MarkConstant()

func (Term) String 

func (t Term) String(r Resolver) string

func (*Term) WireID 

func (t *Term) WireID() int

type UnsatisfiedConstraintError 

type UnsatisfiedConstraintError struct {
	Err       error
	CID       int     // constraint ID
	DebugInfo *string // optional debug info
}

UnsatisfiedConstraintError wraps an error with useful metadata on the unsatisfied constraint

func (*UnsatisfiedConstraintError) Error 

func (r *UnsatisfiedConstraintError) Error() string

type WriterCounter 

type WriterCounter struct {
	W io.Writer
	N int64
}

func (*WriterCounter) Write 

func (w *WriterCounter) Write(p []byte) (n int, err error)

Source Files

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