remove Amino (#265)

Removes Amino and adds varint utility-functions instead, keeping the same serialized format. Partial fix for #242.

The last vestige of Amino is in the proof handling, namely `AbsenceOp` and `ValueOp`, which are structs encoded/decoded with Amino.

docs/node/node.md

@@ -34,43 +34,43 @@ Every node is persisted by encoding the key, version, height, size and hash. If
 ```golang
 // Writes the node as a serialized byte slice to the supplied io.Writer.
 func (node *Node) writeBytes(w io.Writer) error {
-	cause := amino.EncodeInt8(w, node.height)
+	cause := encodeVarint(w, node.height)
 	if cause != nil {
 		return errors.Wrap(cause, "writing height")
 	}
-	cause = amino.EncodeVarint(w, node.size)
+	cause = encodeVarint(w, node.size)
 	if cause != nil {
 		return errors.Wrap(cause, "writing size")
 	}
-	cause = amino.EncodeVarint(w, node.version)
+	cause = encodeVarint(w, node.version)
 	if cause != nil {
 		return errors.Wrap(cause, "writing version")
 	}
 
 	// Unlike writeHashBytes, key is written for inner nodes.
-	cause = amino.EncodeByteSlice(w, node.key)
+	cause = encodeBytes(w, node.key)
 	if cause != nil {
 		return errors.Wrap(cause, "writing key")
 	}
 
 	if node.isLeaf() {
-		cause = amino.EncodeByteSlice(w, node.value)
+		cause = encodeBytes(w, node.value)
 		if cause != nil {
 			return errors.Wrap(cause, "writing value")
 		}
 	} else {
 		if node.leftHash == nil {
 			panic("node.leftHash was nil in writeBytes")
 		}
-		cause = amino.EncodeByteSlice(w, node.leftHash)
+		cause = encodeBytes(w, node.leftHash)
 		if cause != nil {
 			return errors.Wrap(cause, "writing left hash")
 		}
 
 		if node.rightHash == nil {
 			panic("node.rightHash was nil in writeBytes")
 		}
-		cause = amino.EncodeByteSlice(w, node.rightHash)
+		cause = encodeBytes(w, node.rightHash)
 		if cause != nil {
 			return errors.Wrap(cause, "writing right hash")
 		}
@@ -87,42 +87,42 @@ A node's hash is calculated by hashing the height, size, and version of the node
 // Writes the node's hash to the given io.Writer. This function expects
 // child hashes to be already set.
 func (node *Node) writeHashBytes(w io.Writer) error {
-	err := amino.EncodeInt8(w, node.height)
+	err := encodeVarint(w, node.height)
 	if err != nil {
 		return errors.Wrap(err, "writing height")
 	}
-	err = amino.EncodeVarint(w, node.size)
+	err = encodeVarint(w, node.size)
 	if err != nil {
 		return errors.Wrap(err, "writing size")
 	}
-	err = amino.EncodeVarint(w, node.version)
+	err = encodeVarint(w, node.version)
 	if err != nil {
 		return errors.Wrap(err, "writing version")
 	}
 
 	// Key is not written for inner nodes, unlike writeBytes.
 
 	if node.isLeaf() {
-		err = amino.EncodeByteSlice(w, node.key)
+		err = encodeBytes(w, node.key)
 		if err != nil {
 			return errors.Wrap(err, "writing key")
 		}
 		// Indirection needed to provide proofs without values.
 		// (e.g. proofLeafNode.ValueHash)
 		valueHash := tmhash.Sum(node.value)
-		err = amino.EncodeByteSlice(w, valueHash)
+		err = encodeBytes(w, valueHash)
 		if err != nil {
 			return errors.Wrap(err, "writing value")
 		}
 	} else {
 		if node.leftHash == nil || node.rightHash == nil {
 			panic("Found an empty child hash")
 		}
-		err = amino.EncodeByteSlice(w, node.leftHash)
+		err = encodeBytes(w, node.leftHash)
 		if err != nil {
 			return errors.Wrap(err, "writing left hash")
 		}
-		err = amino.EncodeByteSlice(w, node.rightHash)
+		err = encodeBytes(w, node.rightHash)
 		if err != nil {
 			return errors.Wrap(err, "writing right hash")
 		}

encoding.go

@@ -0,0 +1,104 @@
+package iavl
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"math/bits"
+)
+
+// decodeBytes decodes a varint length-prefixed byte slice, returning it along with the number
+// of input bytes read.
+func decodeBytes(bz []byte) ([]byte, int, error) {
+	size, n, err := decodeUvarint(bz)
+	if err != nil {
+		return nil, n, err
+	}
+	if int(size) < 0 {
+		return nil, n, fmt.Errorf("invalid negative length %v decoding []byte", size)
+	}
+	if len(bz) < n+int(size) {
+		return nil, n, fmt.Errorf("insufficient bytes decoding []byte of length %v", size)
+	}
+	bz2 := make([]byte, size)
+	copy(bz2, bz[n:n+int(size)])
+	n += int(size)
+	return bz2, n, nil
+}
+
+// decodeUvarint decodes a varint-encoded unsigned integer from a byte slice, returning it and the
+// number of bytes decoded.
+func decodeUvarint(bz []byte) (uint64, int, error) {
+	u, n := binary.Uvarint(bz)
+	if n == 0 {
+		// buf too small
+		return u, n, errors.New("buffer too small")
+	} else if n < 0 {
+		// value larger than 64 bits (overflow)
+		// and -n is the number of bytes read
+		n = -n
+		return u, n, errors.New("EOF decoding uvarint")
+	}
+	return u, n, nil
+}
+
+// decodeVarint decodes a varint-encoded integer from a byte slice, returning it and the number of
+// bytes decoded.
+func decodeVarint(bz []byte) (int64, int, error) {
+	i, n := binary.Varint(bz)
+	if n == 0 {
+		return i, n, errors.New("buffer too small")
+	} else if n < 0 {
+		// value larger than 64 bits (overflow)
+		// and -n is the number of bytes read
+		n = -n
+		return i, n, errors.New("EOF decoding varint")
+	}
+	return i, n, nil
+}
+
+// encodeBytes writes a varint length-prefixed byte slice to the writer.
+func encodeBytes(w io.Writer, bz []byte) error {
+	err := encodeUvarint(w, uint64(len(bz)))
+	if err != nil {
+		return err
+	}
+	_, err = w.Write(bz)
+	return err
+}
+
+// encodeBytesSize returns the byte size of the given slice including length-prefixing.
+func encodeBytesSize(bz []byte) int {
+	return encodeUvarintSize(uint64(len(bz))) + len(bz)
+}
+
+// encodeUvarint writes a varint-encoded unsigned integer to an io.Writer.
+func encodeUvarint(w io.Writer, u uint64) error {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutUvarint(buf[:], u)
+	_, err := w.Write(buf[0:n])
+	return err
+}
+
+// encodeUvarintSize returns the byte size of the given integer as a varint.
+func encodeUvarintSize(u uint64) int {
+	if u == 0 {
+		return 1
+	}
+	return (bits.Len64(u) + 6) / 7
+}
+
+// encodeVarint writes a varint-encoded integer to an io.Writer.
+func encodeVarint(w io.Writer, i int64) error {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutVarint(buf[:], i)
+	_, err := w.Write(buf[0:n])
+	return err
+}
+
+// encodeVarintSize returns the byte size of the given integer as a varint.
+func encodeVarintSize(i int64) int {
+	var buf [binary.MaxVarintLen64]byte
+	return binary.PutVarint(buf[:], i)
+}

export_test.go

@@ -45,6 +45,7 @@ func setupExportTreeBasic(t require.TestingT) *ImmutableTree {
 }
 
 // setupExportTreeRandom sets up a randomly generated tree.
+// nolint: dupl
 func setupExportTreeRandom(t *testing.T) *ImmutableTree {
 	const (
 		randSeed  = 49872768940 // For deterministic tests