avro

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 Go to latest Published: Aug 4, 2022 License: MIT Imports: 24 Imported by: 0

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A fast Go avro codec

Overview

Install with:

go get github.com/hamba/avro/v2

Usage

type SimpleRecord struct {
	A int64  `avro:"a"`
	B string `avro:"b"`
}

schema, err := avro.Parse(`{
    "type": "record",
    "name": "simple",
    "namespace": "org.hamba.avro",
    "fields" : [
        {"name": "a", "type": "long"},
        {"name": "b", "type": "string"}
    ]
}`)
if err != nil {
	log.Fatal(err)
}

in := SimpleRecord{A: 27, B: "foo"}

data, err := avro.Marshal(schema, in)
if err != nil {
	log.Fatal(err)
}

fmt.Println(data)
// Outputs: [54 6 102 111 111]

out := SimpleRecord{}
err = avro.Unmarshal(schema, data, &out)
if err != nil {
	log.Fatal(err)
}

fmt.Println(out)
// Outputs: {27 foo}

More examples in the godoc.

Types Conversions
Avro Go Struct Go Interface
null nil nil
boolean bool bool
bytes []byte []byte
float float32 float32
double float64 float64
long int64 int64
int int, int32, int16, int8 int
string string string
array []T []interface{}
enum string string
fixed [n]byte []byte
map map[string]T{} map[string]interface{}
record struct map[string]interface{}
union see below see below
int.date time.Time time.Time
int.time-millis time.Duration time.Duration
long.time-micros time.Duration time.Duration
long.timestamp-millis time.Time time.Time
long.timestamp-micros time.Time time.Time
bytes.decimal *big.Rat *big.Rat
fixed.decimal *big.Rat *big.Rat
Unions

The following union types are accepted: map[string]interface{}, *T and interface{}.

  • map[string]interface{}: If the union value is nil, a nil map will be en/decoded. When a non-nil union value is encountered, a single key is en/decoded. The key is the avro type name, or scheam full name in the case of a named schema (enum, fixed or record).
  • *T: This is allowed in a "nullable" union. A nullable union is defined as a two schema union, with one of the types being null (ie. ["null", "string"] or ["string", "null"]), in this case a *T is allowed, with T matching the conversion table above.
  • interface{}: An interface can be provided and the type or name resolved. Primitive types are pre-registered, but named types, maps and slices will need to be registered with the Register function. In the case of arrays and maps the enclosed schema type or name is postfix to the type with a : separator, e.g "map:string". If any type cannot be resolved the map type above is used unless Config.UnionResolutionError is set to true in which case an error is returned.
TextMarshaler and TextUnmarshaler

The interfaces TextMarshaler and TextUnmarshaler are supported for a string schema type. The object will be tested first for implementation of these interfaces, in the case of a string schema, before trying regular encoding and decoding.

Recursive Structs

At this moment recursive structs are not supported. It is planned for the future.

Benchmark

Benchmark source code can be found at: https://github.com/nrwiersma/avro-benchmarks

BenchmarkGoAvroDecode-10       	  495176	      2413 ns/op	     418 B/op	      27 allocs/op
BenchmarkGoAvroEncode-10       	  420168	      2917 ns/op	     948 B/op	      63 allocs/op
BenchmarkGoGenAvroDecode-10    	  757150	      1552 ns/op	     728 B/op	      45 allocs/op
BenchmarkGoGenAvroEncode-10    	 1882940	       639.0 ns/op	     256 B/op	       3 allocs/op
BenchmarkHambaDecode-10        	 3138063	       383.0 ns/op	      64 B/op	       4 allocs/op
BenchmarkHambaEncode-10        	 4377513	       273.3 ns/op	     112 B/op	       1 allocs/op
BenchmarkLinkedinDecode-10     	 1000000	      1109 ns/op	    1688 B/op	      35 allocs/op
BenchmarkLinkedinEncode-10     	 2641016	       456.0 ns/op	     248 B/op	       5 allocs/op

Always benchmark with your own workload. The result depends heavily on the data input.

EXPERIMENTAL - Go structs generation

Go structs can be generated for you from the schema. The types generated follow the same logic in types conversions

Install the struct generator with:

go install github.com/hamba/avro/v2/cmd/avrogen@<version>

Example usage assuming there's a valid schema in in.avsc:

./app -pkg avro -o bla.go -tags json:snake,yaml:upper-camel in.avsc

Check the options and usage with -h:

avrogen -h

Or use it as a lib in internal commands, it's the gen package

Documentation

Overview

Package avro implements encoding and decoding of Avro as defined by the Avro specification.

See the Avro specification for an understanding of Avro: http://avro.apache.org/docs/current/

Example (Usage) 
package main

import (
	"fmt"
	"log"

	"github.com/Zemanta/avro"
)

var Schema = `{
		"type": "record",
		"name": "simple",
		"namespace": "org.hamba.avro",
		"fields" : [
			{"name": "a", "type": "long"},
			{"name": "b", "type": "string"}
		]
	}`

type SimpleRecord struct {
	A int64  `avro:"a"`
	B string `avro:"b"`
}

func main() {
	schema, err := avro.Parse(Schema)
	if err != nil {
		log.Fatal(err)
	}

	in := SimpleRecord{A: 27, B: "foo"}

	data, err := avro.Marshal(schema, in)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%+v\n", data)

	out := SimpleRecord{}
	err = avro.Unmarshal(schema, data, &out)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%+v\n", out)

}

Output:

[54 6 102 111 111]
{A:27 B:foo}

Index

Examples

Constants

This section is empty.

Variables

View Source 
var DefaultConfig = Config{}.Freeze()

DefaultConfig is the default API.

View Source 
var DefaultSchemaCache = &SchemaCache{}

DefaultSchemaCache is the default cache for schemas.

View Source 
var NoDefault = noDef{}

NoDefault is used when no default exists for a field.

Functions

func Marshal 

func Marshal(schema Schema, v interface{}) ([]byte, error)

Marshal returns the Avro encoding of v.

Example 
package main

import (
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := avro.MustParse(`{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`)

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	simple := SimpleRecord{A: 27, B: "foo"}
	b, err := avro.Marshal(schema, simple)
	if err != nil {
		fmt.Println("error:", err)
	}

	fmt.Println(b)

}

Output:

[54 6 102 111 111]

func Register 

func Register(name string, obj interface{})

Register registers names to their types for resolution. All primitive types are pre-registered.

Example 
package main

import (
	"fmt"
	"log"

	"github.com/Zemanta/avro"
)

func main() {
	data := []byte{0x02, 0x02} // Your Avro data here
	schema := avro.MustParse(`["null", {"type":"enum", "name": "test", "symbols": ["A", "B"]}]`)

	avro.Register("test", "") // Register the name test as a string type

	var result interface{}
	err := avro.Unmarshal(schema, data, &result)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(result)

}

Output:

B

func Unmarshal 

func Unmarshal(schema Schema, data []byte, v interface{}) error

Unmarshal parses the Avro encoded data and stores the result in the value pointed to by v. If v is nil or not a pointer, Unmarshal returns an error.

Example 
package main

import (
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := avro.MustParse(`{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`)

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	data := []byte{0x36, 0x06, 0x66, 0x6F, 0x6F} // Your Avro data here
	simple := SimpleRecord{}
	if err := avro.Unmarshal(schema, data, &simple); err != nil {
		fmt.Println("error:", err)
	}

	fmt.Printf("%+v", simple)

}

Output:

{A:27 B:foo}

Types

type API 

type API interface {
	// Marshal returns the Avro encoding of v.
	Marshal(schema Schema, v interface{}) ([]byte, error)

	// Unmarshal parses the Avro encoded data and stores the result in the value pointed to by v.
	// If v is nil or not a pointer, Unmarshal returns an error.
	Unmarshal(schema Schema, data []byte, v interface{}) error

	// NewEncoder returns a new encoder that writes to w using schema.
	NewEncoder(schema Schema, w io.Writer) *Encoder

	// NewDecoder returns a new decoder that reads from reader r using schema.
	NewDecoder(schema Schema, r io.Reader) *Decoder

	// DecoderOf returns the value decoder for a given schema and type.
	DecoderOf(schema Schema, typ reflect2.Type) ValDecoder

	// EncoderOf returns the value encoder for a given schema and type.
	EncoderOf(schema Schema, tpy reflect2.Type) ValEncoder

	// Register registers names to their types for resolution. All primitive types are pre-registered.
	Register(name string, obj interface{})
}

API represents a frozen Config.

type ArraySchema 

type ArraySchema struct {
	// contains filtered or unexported fields
}

ArraySchema is an Avro array type schema.

func NewArraySchema 

func NewArraySchema(items Schema, opts ...SchemaOption) *ArraySchema

NewArraySchema creates an array schema instance.

func (*ArraySchema) Fingerprint 

func (s *ArraySchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*ArraySchema) FingerprintUsing 

func (s *ArraySchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*ArraySchema) Items 

func (s *ArraySchema) Items() Schema

Items returns the items schema of an array.

func (*ArraySchema) MarshalJSON 

func (s *ArraySchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (ArraySchema) Prop 

func (p ArraySchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*ArraySchema) String 

func (s *ArraySchema) String() string

String returns the canonical form of the schema.

func (*ArraySchema) Type 

func (s *ArraySchema) Type() Type

Type returns the type of the schema.

type Config 

type Config struct {
	// TagKey is the struct tag key used when en/decoding structs.
	// This defaults to "avro".
	TagKey string

	// BlockLength is the length of blocks for maps and arrays.
	// This defaults to 100.
	BlockLength int

	// UnionResolutionError determines if an error will be returned
	// when a type cannot be resolved while decoding a union.
	UnionResolutionError bool
}

Config customises how the codec should behave.

func (Config) Freeze 

func (c Config) Freeze() API

Freeze makes the configuration immutable.

type DecimalLogicalSchema 

type DecimalLogicalSchema struct {
	// contains filtered or unexported fields
}

DecimalLogicalSchema is a decimal logical type.

func NewDecimalLogicalSchema 

func NewDecimalLogicalSchema(prec, scale int) *DecimalLogicalSchema

NewDecimalLogicalSchema creates a new decimal logical schema instance.

func (*DecimalLogicalSchema) Precision 

func (s *DecimalLogicalSchema) Precision() int

Precision returns the precision of the decimal logical schema.

func (*DecimalLogicalSchema) Scale 

func (s *DecimalLogicalSchema) Scale() int

Scale returns the scale of the decimal logical schema.

func (*DecimalLogicalSchema) String 

func (s *DecimalLogicalSchema) String() string

String returns the canonical form of the logical schema.

func (*DecimalLogicalSchema) Type 

func (s *DecimalLogicalSchema) Type() LogicalType

Type returns the type of the logical schema.

type Decoder 

type Decoder struct {
	// contains filtered or unexported fields
}

Decoder reads and decodes Avro values from an input stream.

func NewDecoder 

func NewDecoder(s string, r io.Reader) (*Decoder, error)

NewDecoder returns a new decoder that reads from reader r using schema s.

Example 
package main

import (
	"bytes"
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := `{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	r := bytes.NewReader([]byte{}) // Your reader goes here
	decoder, err := avro.NewDecoder(schema, r)
	if err != nil {
		fmt.Println("error:", err)
	}

	simple := SimpleRecord{}
	if err := decoder.Decode(&simple); err != nil {
		fmt.Println("error:", err)
	}

	fmt.Printf("%+v", simple)
}

Output:

func NewDecoderForSchema 

func NewDecoderForSchema(schema Schema, reader io.Reader) *Decoder

NewDecoderForSchema returns a new decoder that reads from r using schema.

Example 
package main

import (
	"bytes"
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := avro.MustParse(`{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`)

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	r := bytes.NewReader([]byte{0x36, 0x06, 0x66, 0x6F, 0x6F}) // Your reader goes here
	decoder := avro.NewDecoderForSchema(schema, r)

	simple := SimpleRecord{}
	if err := decoder.Decode(&simple); err != nil {
		fmt.Println("error:", err)
	}

	fmt.Printf("%+v", simple)

}

Output:

{A:27 B:foo}

func (*Decoder) Decode 

func (d *Decoder) Decode(obj interface{}) error

Decode reads the next Avro encoded value from its input and stores it in the value pointed to by v.

type Encoder 

type Encoder struct {
	// contains filtered or unexported fields
}

Encoder writes Avro values to an output stream.

func NewEncoder 

func NewEncoder(s string, w io.Writer) (*Encoder, error)

NewEncoder returns a new encoder that writes to w using schema s.

Example 
package main

import (
	"bytes"
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := `{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	w := &bytes.Buffer{}
	encoder, err := avro.NewEncoder(schema, w)
	if err != nil {
		fmt.Println("error:", err)
	}

	simple := SimpleRecord{A: 27, B: "foo"}
	if err := encoder.Encode(simple); err != nil {
		fmt.Println("error:", err)
	}

	fmt.Println(w.Bytes())

}

Output:

[54 6 102 111 111]

func NewEncoderForSchema 

func NewEncoderForSchema(schema Schema, w io.Writer) *Encoder

NewEncoderForSchema returns a new encoder that writes to w using schema.

Example 
package main

import (
	"bytes"
	"fmt"

	"github.com/Zemanta/avro"
)

func main() {
	schema := avro.MustParse(`{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`)

	type SimpleRecord struct {
		A int64  `avro:"a"`
		B string `avro:"b"`
	}

	w := &bytes.Buffer{}
	encoder := avro.NewEncoderForSchema(schema, w)

	simple := SimpleRecord{A: 27, B: "foo"}
	if err := encoder.Encode(simple); err != nil {
		fmt.Println("error:", err)
	}

	fmt.Println(w.Bytes())

}

Output:

[54 6 102 111 111]

func (*Encoder) Encode 

func (e *Encoder) Encode(v interface{}) error

Encode writes the Avro encoding of v to the stream.

type EnumSchema 

type EnumSchema struct {
	// contains filtered or unexported fields
}

EnumSchema is an Avro enum type schema.

func NewEnumSchema 

func NewEnumSchema(name, namespace string, symbols []string, opts ...SchemaOption) (*EnumSchema, error)

NewEnumSchema creates a new enum schema instance.

func (EnumSchema) Aliases 

func (n EnumSchema) Aliases() []string

Aliases returns the fully qualified aliases of a schema.

func (*EnumSchema) Default 

func (s *EnumSchema) Default() string

Default returns the default of an enum or an empty string.

func (*EnumSchema) Doc 

func (s *EnumSchema) Doc() string

Doc returns the schema doc.

func (*EnumSchema) Fingerprint 

func (s *EnumSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*EnumSchema) FingerprintUsing 

func (s *EnumSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (EnumSchema) FullName 

func (n EnumSchema) FullName() string

FullName returns the fully qualified name of a schema.

func (*EnumSchema) MarshalJSON 

func (s *EnumSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (EnumSchema) Name 

func (n EnumSchema) Name() string

Name returns the name of a schema.

func (EnumSchema) Namespace 

func (n EnumSchema) Namespace() string

Namespace returns the namespace of a schema.

func (EnumSchema) Prop 

func (p EnumSchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*EnumSchema) String 

func (s *EnumSchema) String() string

String returns the canonical form of the schema.

func (*EnumSchema) Symbols 

func (s *EnumSchema) Symbols() []string

Symbols returns the symbols of an enum.

func (*EnumSchema) Type 

func (s *EnumSchema) Type() Type

Type returns the type of the schema.

type Field 

type Field struct {
	// contains filtered or unexported fields
}

Field is an Avro record type field.

func NewField 

func NewField(name string, typ Schema, opts ...SchemaOption) (*Field, error)

NewField creates a new field instance.

func (*Field) Aliases 

func (f *Field) Aliases() []string

Aliases return the field aliases.

func (*Field) Default 

func (f *Field) Default() interface{}

Default returns the default of a field or nil.

The only time a nil default is valid is for a Null Type.

func (*Field) Doc 

func (f *Field) Doc() string

Doc returns the documentation of a field.

func (*Field) HasDefault 

func (f *Field) HasDefault() bool

HasDefault determines if the field has a default value.

func (*Field) MarshalJSON 

func (f *Field) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (*Field) Name 

func (f *Field) Name() string

Name returns the name of a field.

func (*Field) Order 

func (f *Field) Order() Order

Order returns the field order.

func (Field) Prop 

func (p Field) Prop(name string) interface{}

Prop gets a property from the schema.

func (*Field) String 

func (f *Field) String() string

String returns the canonical form of a field.

func (*Field) Type 

func (f *Field) Type() Schema

Type returns the schema of a field.

type FingerprintType 

type FingerprintType string

FingerprintType is a fingerprinting algorithm. 

const (
	CRC64Avro FingerprintType = "CRC64-AVRO"
	MD5       FingerprintType = "MD5"
	SHA256    FingerprintType = "SHA256"
)

Fingerprint type constants.

type FixedSchema 

type FixedSchema struct {
	// contains filtered or unexported fields
}

FixedSchema is an Avro fixed type schema.

func NewFixedSchema 

func NewFixedSchema(
	name, namespace string,
	size int,
	logical LogicalSchema,
	opts ...SchemaOption,
) (*FixedSchema, error)

NewFixedSchema creates a new fixed schema instance.

func (FixedSchema) Aliases 

func (n FixedSchema) Aliases() []string

Aliases returns the fully qualified aliases of a schema.

func (*FixedSchema) Fingerprint 

func (s *FixedSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*FixedSchema) FingerprintUsing 

func (s *FixedSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (FixedSchema) FullName 

func (n FixedSchema) FullName() string

FullName returns the fully qualified name of a schema.

func (*FixedSchema) Logical 

func (s *FixedSchema) Logical() LogicalSchema

Logical returns the logical schema or nil.

func (*FixedSchema) MarshalJSON 

func (s *FixedSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (FixedSchema) Name 

func (n FixedSchema) Name() string

Name returns the name of a schema.

func (FixedSchema) Namespace 

func (n FixedSchema) Namespace() string

Namespace returns the namespace of a schema.

func (FixedSchema) Prop 

func (p FixedSchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*FixedSchema) Size 

func (s *FixedSchema) Size() int

Size returns the number of bytes of the fixed schema.

func (*FixedSchema) String 

func (s *FixedSchema) String() string

String returns the canonical form of the schema.

func (*FixedSchema) Type 

func (s *FixedSchema) Type() Type

Type returns the type of the schema.

type LogicalSchema 

type LogicalSchema interface {
	// Type returns the type of the logical schema.
	Type() LogicalType

	// String returns the canonical form of the logical schema.
	String() string
}

LogicalSchema represents an Avro schema with a logical type.

type LogicalType 

type LogicalType string

LogicalType is a schema logical type. 

const (
	Decimal         LogicalType = "decimal"
	UUID            LogicalType = "uuid"
	Date            LogicalType = "date"
	TimeMillis      LogicalType = "time-millis"
	TimeMicros      LogicalType = "time-micros"
	TimestampMillis LogicalType = "timestamp-millis"
	TimestampMicros LogicalType = "timestamp-micros"
	Duration        LogicalType = "duration"
)

Schema logical type constants.

type LogicalTypeSchema 

type LogicalTypeSchema interface {
	// Logical returns the logical schema or nil.
	Logical() LogicalSchema
}

LogicalTypeSchema represents a schema that can contain a logical type.

type MapSchema 

type MapSchema struct {
	// contains filtered or unexported fields
}

MapSchema is an Avro map type schema.

func NewMapSchema 

func NewMapSchema(values Schema, opts ...SchemaOption) *MapSchema

NewMapSchema creates a map schema instance.

func (*MapSchema) Fingerprint 

func (s *MapSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*MapSchema) FingerprintUsing 

func (s *MapSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*MapSchema) MarshalJSON 

func (s *MapSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (MapSchema) Prop 

func (p MapSchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*MapSchema) String 

func (s *MapSchema) String() string

String returns the canonical form of the schema.

func (*MapSchema) Type 

func (s *MapSchema) Type() Type

Type returns the type of the schema.

func (*MapSchema) Values 

func (s *MapSchema) Values() Schema

Values returns the values schema of a map.

type Message 

type Message struct {
	// contains filtered or unexported fields
}

Message is an Avro protocol message.

func NewMessage 

func NewMessage(req *RecordSchema, resp Schema, errors *UnionSchema, oneWay bool, opts ...ProtocolOption) *Message

NewMessage creates a protocol message instance.

func (*Message) Doc 

func (m *Message) Doc() string

Doc returns the message doc.

func (*Message) Errors 

func (m *Message) Errors() *UnionSchema

Errors returns the message errors union schema.

func (*Message) OneWay 

func (m *Message) OneWay() bool

OneWay determines of the message is a one way message.

func (Message) Prop 

func (p Message) Prop(name string) interface{}

Prop gets a property from the schema.

func (*Message) Request 

func (m *Message) Request() *RecordSchema

Request returns the message request schema.

func (*Message) Response 

func (m *Message) Response() Schema

Response returns the message response schema.

func (*Message) String 

func (m *Message) String() string

String returns the canonical form of the message.

type NamedSchema 

type NamedSchema interface {
	Schema
	PropertySchema

	// Name returns the name of the schema.
	Name() string

	// Namespace returns the namespace of a schema.
	Namespace() string

	// FullName returns the full qualified name of a schema.
	FullName() string
}

NamedSchema represents a schema with a name.

type NullSchema 

type NullSchema struct {
	// contains filtered or unexported fields
}

NullSchema is an Avro null type schema.

func (*NullSchema) Fingerprint 

func (s *NullSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*NullSchema) FingerprintUsing 

func (s *NullSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*NullSchema) MarshalJSON 

func (s *NullSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (*NullSchema) String 

func (s *NullSchema) String() string

String returns the canonical form of the schema.

func (*NullSchema) Type 

func (s *NullSchema) Type() Type

Type returns the type of the schema.

type Order 

type Order string

Order is a field order. 

const (
	Asc    Order = "ascending"
	Desc   Order = "descending"
	Ignore Order = "ignore"
)

Field orders.

type PrimitiveLogicalSchema 

type PrimitiveLogicalSchema struct {
	// contains filtered or unexported fields
}

PrimitiveLogicalSchema is a logical type with no properties.

func NewPrimitiveLogicalSchema 

func NewPrimitiveLogicalSchema(typ LogicalType) *PrimitiveLogicalSchema

NewPrimitiveLogicalSchema creates a new primitive logical schema instance.

func (*PrimitiveLogicalSchema) String 

func (s *PrimitiveLogicalSchema) String() string

String returns the canonical form of the logical schema.

func (*PrimitiveLogicalSchema) Type 

func (s *PrimitiveLogicalSchema) Type() LogicalType

Type returns the type of the logical schema.

type PrimitiveSchema 

type PrimitiveSchema struct {
	// contains filtered or unexported fields
}

PrimitiveSchema is an Avro primitive type schema.

func NewPrimitiveSchema 

func NewPrimitiveSchema(t Type, l LogicalSchema, s SqlSchema, opts ...SchemaOption) *PrimitiveSchema

NewPrimitiveSchema creates a new PrimitiveSchema.

func (*PrimitiveSchema) Fingerprint 

func (s *PrimitiveSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*PrimitiveSchema) FingerprintUsing 

func (s *PrimitiveSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*PrimitiveSchema) Logical 

func (s *PrimitiveSchema) Logical() LogicalSchema

Logical returns the logical schema or nil.

func (*PrimitiveSchema) MarshalJSON 

func (s *PrimitiveSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (PrimitiveSchema) Prop 

func (p PrimitiveSchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*PrimitiveSchema) Sql 

func (s *PrimitiveSchema) Sql() SqlSchema

Sql returns the Sql schema or nil.

func (*PrimitiveSchema) String 

func (s *PrimitiveSchema) String() string

String returns the canonical form of the schema.

func (*PrimitiveSchema) Type 

func (s *PrimitiveSchema) Type() Type

Type returns the type of the schema.

type PrimitiveSqlSchema 

type PrimitiveSqlSchema struct {
	// contains filtered or unexported fields
}

SqlLogicalSchema is a sql type with no properties.

func NewPrimitiveSqlSchema 

func NewPrimitiveSqlSchema(typ SqlType) *PrimitiveSqlSchema

NewPrimitiveSqlSchema creates a new primitive sql schema instance.

func (*PrimitiveSqlSchema) String 

func (s *PrimitiveSqlSchema) String() string

String returns the canonical form of the sql schema.

func (*PrimitiveSqlSchema) Type 

func (s *PrimitiveSqlSchema) Type() SqlType

Type returns the type of the sql schema.

type PropertySchema 

type PropertySchema interface {
	// Prop gets a property from the schema.
	Prop(string) interface{}
}

PropertySchema represents a schema with properties.

type Protocol 

type Protocol struct {
	// contains filtered or unexported fields
}

Protocol is an Avro protocol.

func MustParseProtocol 

func MustParseProtocol(protocol string) *Protocol

MustParseProtocol parses an Avro protocol, panicing if there is an error.

func NewProtocol 

func NewProtocol(
	name, namepsace string,
	types []NamedSchema,
	messages map[string]*Message,
	opts ...ProtocolOption,
) (*Protocol, error)

NewProtocol creates a protocol instance.

func ParseProtocol 

func ParseProtocol(protocol string) (*Protocol, error)

ParseProtocol parses an Avro protocol.

func ParseProtocolFile 

func ParseProtocolFile(path string) (*Protocol, error)

ParseProtocolFile parses an Avro protocol from a file.

func (Protocol) Aliases 

func (n Protocol) Aliases() []string

Aliases returns the fully qualified aliases of a schema.

func (*Protocol) Doc 

func (p *Protocol) Doc() string

Doc returns the protocol doc.

func (Protocol) FullName 

func (n Protocol) FullName() string

FullName returns the fully qualified name of a schema.

func (*Protocol) Hash 

func (p *Protocol) Hash() string

Hash returns the MD5 hash of the protocol.

func (*Protocol) Message 

func (p *Protocol) Message(name string) *Message

Message returns a message with the given name or nil.

func (Protocol) Name 

func (n Protocol) Name() string

Name returns the name of a schema.

func (Protocol) Namespace 

func (n Protocol) Namespace() string

Namespace returns the namespace of a schema.

func (Protocol) Prop 

func (p Protocol) Prop(name string) interface{}

Prop gets a property from the schema.

func (*Protocol) String 

func (p *Protocol) String() string

String returns the canonical form of the protocol.

type ProtocolOption 

type ProtocolOption func(*protocolConfig)

ProtocolOption is a function that sets a protocol option.

func WithProtoDoc 

func WithProtoDoc(doc string) ProtocolOption

WithProtoDoc sets the doc on a protocol.

func WithProtoProps 

func WithProtoProps(props map[string]interface{}) ProtocolOption

WithProtoProps sets the properties on a protocol.

type Reader 

type Reader struct {
	Error error
	// contains filtered or unexported fields
}

Reader is an Avro specific io.Reader.

func NewReader 

func NewReader(r io.Reader, bufSize int, opts ...ReaderFunc) *Reader

NewReader creates a new Reader.

func (*Reader) Read 

func (r *Reader) Read(b []byte)

Read reads data into the given bytes.

func (*Reader) ReadArrayCB 

func (r *Reader) ReadArrayCB(callback func(*Reader) bool)

ReadArrayCB reads an array with a callback per item.

func (*Reader) ReadBlockHeader 

func (r *Reader) ReadBlockHeader() (int64, int64)

ReadBlockHeader reads a Block Header from the Reader.

func (*Reader) ReadBool 

func (r *Reader) ReadBool() bool

ReadBool reads a Bool from the Reader.

func (*Reader) ReadBytes 

func (r *Reader) ReadBytes() []byte

ReadBytes reads Bytes from the Reader.

func (*Reader) ReadDouble 

func (r *Reader) ReadDouble() float64

ReadDouble reads a Double from the Reader.

func (*Reader) ReadFloat 

func (r *Reader) ReadFloat() float32

ReadFloat reads a Float from the Reader.

func (*Reader) ReadInt 

func (r *Reader) ReadInt() int32

ReadInt reads an Int from the Reader.

func (*Reader) ReadLong 

func (r *Reader) ReadLong() int64

ReadLong reads a Long from the Reader.

func (*Reader) ReadMapCB 

func (r *Reader) ReadMapCB(callback func(*Reader, string) bool)

ReadMapCB reads an array with a callback per item.

func (*Reader) ReadNext 

func (r *Reader) ReadNext(schema Schema) interface{}

ReadNext reads the next Avro element as a generic interface.

func (*Reader) ReadString 

func (r *Reader) ReadString() string

ReadString reads a String from the Reader.

func (*Reader) ReadVal 

func (r *Reader) ReadVal(schema Schema, obj interface{})

ReadVal parses Avro value and stores the result in the value pointed to by obj.

func (*Reader) ReportError 

func (r *Reader) ReportError(operation, msg string)

ReportError record a error in iterator instance with current position.

func (*Reader) Reset 

func (r *Reader) Reset(b []byte) *Reader

Reset resets a Reader with a new byte array attached.

func (*Reader) SkipBool 

func (r *Reader) SkipBool()

SkipBool skips a Bool in the reader.

func (*Reader) SkipBytes 

func (r *Reader) SkipBytes()

SkipBytes skips Bytes in the reader.

func (*Reader) SkipDouble 

func (r *Reader) SkipDouble()

SkipDouble skips a Double in the reader.

func (*Reader) SkipFloat 

func (r *Reader) SkipFloat()

SkipFloat skips a Float in the reader.

func (*Reader) SkipInt 

func (r *Reader) SkipInt()

SkipInt skips an Int in the reader.

func (*Reader) SkipLong 

func (r *Reader) SkipLong()

SkipLong skips a Long in the reader.

func (*Reader) SkipNBytes 

func (r *Reader) SkipNBytes(n int)

SkipNBytes skips the given number of bytes in the reader.

func (*Reader) SkipString 

func (r *Reader) SkipString()

SkipString skips a String in the reader.

type ReaderFunc 

type ReaderFunc func(r *Reader)

ReaderFunc is a function used to customize the Reader.

func WithReaderConfig 

func WithReaderConfig(cfg API) ReaderFunc

WithReaderConfig specifies the configuration to use with a reader.

type RecordSchema 

type RecordSchema struct {
	// contains filtered or unexported fields
}

RecordSchema is an Avro record type schema.

func NewErrorRecordSchema 

func NewErrorRecordSchema(name, namespace string, fields []*Field, opts ...SchemaOption) (*RecordSchema, error)

NewErrorRecordSchema creates a new error record schema instance.

func NewRecordSchema 

func NewRecordSchema(name, namespace string, fields []*Field, opts ...SchemaOption) (*RecordSchema, error)

NewRecordSchema creates a new record schema instance.

func (RecordSchema) Aliases 

func (n RecordSchema) Aliases() []string

Aliases returns the fully qualified aliases of a schema.

func (*RecordSchema) Doc 

func (s *RecordSchema) Doc() string

Doc returns the documentation of a record.

func (*RecordSchema) Fields 

func (s *RecordSchema) Fields() []*Field

Fields returns the fields of a record.

func (*RecordSchema) Fingerprint 

func (s *RecordSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*RecordSchema) FingerprintUsing 

func (s *RecordSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (RecordSchema) FullName 

func (n RecordSchema) FullName() string

FullName returns the fully qualified name of a schema.

func (*RecordSchema) IsError 

func (s *RecordSchema) IsError() bool

IsError determines is this is an error record.

func (*RecordSchema) MarshalJSON 

func (s *RecordSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (RecordSchema) Name 

func (n RecordSchema) Name() string

Name returns the name of a schema.

func (RecordSchema) Namespace 

func (n RecordSchema) Namespace() string

Namespace returns the namespace of a schema.

func (RecordSchema) Prop 

func (p RecordSchema) Prop(name string) interface{}

Prop gets a property from the schema.

func (*RecordSchema) String 

func (s *RecordSchema) String() string

String returns the canonical form of the schema.

func (*RecordSchema) Type 

func (s *RecordSchema) Type() Type

Type returns the type of the schema.

type RefSchema 

type RefSchema struct {
	// contains filtered or unexported fields
}

RefSchema is a reference to a named Avro schema.

func NewRefSchema 

func NewRefSchema(schema NamedSchema) *RefSchema

NewRefSchema creates a ref schema instance.

func (*RefSchema) Fingerprint 

func (s *RefSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*RefSchema) FingerprintUsing 

func (s *RefSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*RefSchema) MarshalJSON 

func (s *RefSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (*RefSchema) Schema 

func (s *RefSchema) Schema() Schema

Schema returns the schema being referenced.

func (*RefSchema) String 

func (s *RefSchema) String() string

String returns the canonical form of the schema.

func (*RefSchema) Type 

func (s *RefSchema) Type() Type

Type returns the type of the schema.

type Schema 

type Schema interface {
	// Type returns the type of the schema.
	Type() Type

	// String returns the canonical form of the schema.
	String() string

	// Fingerprint returns the SHA256 fingerprint of the schema.
	Fingerprint() [32]byte

	// FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.
	FingerprintUsing(FingerprintType) ([]byte, error)
}

Schema represents an Avro schema.

func MustParse 

func MustParse(schema string) Schema

MustParse parses a schema string, panicing if there is an error.

func Parse 

func Parse(schema string) (Schema, error)

Parse parses a schema string.

Example 
package main

import (
	"fmt"
	"log"

	"github.com/Zemanta/avro"
)

func main() {
	schema, err := avro.Parse(`{
	    "type": "record",
	    "name": "simple",
	    "namespace": "org.hamba.avro",
	    "fields" : [
	        {"name": "a", "type": "long"},
	        {"name": "b", "type": "string"}
	    ]
	}`)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(schema.Type())
	// Outputs: record
}

Output:

func ParseFiles 

func ParseFiles(paths ...string) (Schema, error)

ParseFiles parses the schemas in the files, in the order they appear, returning the last schema.

This is useful when your schemas rely on other schemas.

func ParseWithCache 

func ParseWithCache(schema, namespace string, cache *SchemaCache) (Schema, error)

ParseWithCache parses a schema string using the given namespace and schema cache.

type SchemaCache 

type SchemaCache struct {
	// contains filtered or unexported fields
}

SchemaCache is a cache of schemas.

func (*SchemaCache) Add 

func (c *SchemaCache) Add(name string, schema Schema)

Add adds a schema to the cache with the given name.

func (*SchemaCache) Get 

func (c *SchemaCache) Get(name string) Schema

Get returns the Schema if it exists.

type SchemaCompatibility 

type SchemaCompatibility struct {
	// contains filtered or unexported fields
}

SchemaCompatibility determines the compatibility of schemas.

func NewSchemaCompatibility 

func NewSchemaCompatibility() *SchemaCompatibility

NewSchemaCompatibility creates a new schema compatibility instance.

func (*SchemaCompatibility) Compatible 

func (c *SchemaCompatibility) Compatible(reader, writer Schema) error

Compatible determines the compatibility if the reader and writer schemas.

type SchemaOption 

type SchemaOption func(*schemaConfig)

SchemaOption is a function that sets a schema option.

func WithAliases 

func WithAliases(aliases []string) SchemaOption

WithAliases sets the aliases on a schema.

func WithDefault 

func WithDefault(def interface{}) SchemaOption

WithDefault sets the default on a schema.

func WithDoc 

func WithDoc(doc string) SchemaOption

WithDoc sets the doc on a schema.

func WithOrder 

func WithOrder(order Order) SchemaOption

WithOrder sets the order on a schema.

func WithProps 

func WithProps(props map[string]interface{}) SchemaOption

WithProps sets the properties on a schema.

type Schemas 

type Schemas []Schema

Schemas is a slice of Schemas.

func (Schemas) Get 

func (s Schemas) Get(name string) (Schema, int)

Get gets a schema and position by type or name if it is a named schema.

type SqlSchema 

type SqlSchema interface {
	// Type returns the type of the sql schema.
	Type() SqlType

	// String returns the canonical form of the Sql schema.
	String() string
}

SqlSchema represents an Avro schema with a sql type.

type SqlType 

type SqlType string

SqlType is a schema sql type. 

const (
	Json SqlType = "JSON"
)

Schema sql type constants.

type SqlTypeSchema 

type SqlTypeSchema interface {
	// Sql returns the sql schema or nil.
	Sql() SqlSchema
}

SqlTypeSchema represents a schema that can contain a sql type.

type Type 

type Type string

Type is a schema type. 

const (
	Record  Type = "record"
	Error   Type = "error"
	Ref     Type = "<ref>"
	Enum    Type = "enum"
	Array   Type = "array"
	Map     Type = "map"
	Union   Type = "union"
	Fixed   Type = "fixed"
	String  Type = "string"
	Bytes   Type = "bytes"
	Int     Type = "int"
	Long    Type = "long"
	Float   Type = "float"
	Double  Type = "double"
	Boolean Type = "boolean"
	Null    Type = "null"
)

Schema type constants.

type TypeResolver 

type TypeResolver struct {
	// contains filtered or unexported fields
}

TypeResolver resolves types by name.

func NewTypeResolver 

func NewTypeResolver() *TypeResolver

NewTypeResolver creates a new type resolver with all primitive types registered.

func (*TypeResolver) Name 

func (r *TypeResolver) Name(typ reflect2.Type) ([]string, error)

Name gets the name for a type, or an error.

func (*TypeResolver) Register 

func (r *TypeResolver) Register(name string, obj interface{})

Register registers names to their types for resolution.

func (*TypeResolver) Type 

func (r *TypeResolver) Type(name string) (reflect2.Type, error)

Type gets the type for a name, or an error.

type UnionSchema 

type UnionSchema struct {
	// contains filtered or unexported fields
}

UnionSchema is an Avro union type schema.

func NewUnionSchema 

func NewUnionSchema(types []Schema) (*UnionSchema, error)

NewUnionSchema creates a union schema instance.

func (*UnionSchema) Fingerprint 

func (s *UnionSchema) Fingerprint() [32]byte

Fingerprint returns the SHA256 fingerprint of the schema.

func (*UnionSchema) FingerprintUsing 

func (s *UnionSchema) FingerprintUsing(typ FingerprintType) ([]byte, error)

FingerprintUsing returns the fingerprint of the schema using the given algorithm or an error.

func (*UnionSchema) Indices 

func (s *UnionSchema) Indices() (null, typ int)

Indices returns the index of the null and type schemas for a nullable schema. For non-nullable schemas 0 is returned for both.

func (*UnionSchema) MarshalJSON 

func (s *UnionSchema) MarshalJSON() ([]byte, error)

MarshalJSON marshals the schema to json.

func (*UnionSchema) Nullable 

func (s *UnionSchema) Nullable() bool

Nullable returns the Schema if the union is nullable, otherwise nil.

func (*UnionSchema) String 

func (s *UnionSchema) String() string

String returns the canonical form of the schema.

func (*UnionSchema) Type 

func (s *UnionSchema) Type() Type

Type returns the type of the schema.

func (*UnionSchema) Types 

func (s *UnionSchema) Types() Schemas

Types returns the types of a union.

type ValDecoder 

type ValDecoder interface {
	Decode(ptr unsafe.Pointer, r *Reader)
}

ValDecoder represents an internal value decoder.

You should never use ValDecoder directly.

type ValEncoder 

type ValEncoder interface {
	Encode(ptr unsafe.Pointer, w *Writer)
}

ValEncoder represents an internal value encoder.

You should never use ValEncoder directly.

type Writer 

type Writer struct {
	Error error
	// contains filtered or unexported fields
}

Writer is an Avro specific io.Writer.

func NewWriter 

func NewWriter(out io.Writer, bufSize int, opts ...WriterFunc) *Writer

NewWriter creates a new Writer.

func (*Writer) Buffer 

func (w *Writer) Buffer() []byte

Buffer gets the Writer buffer.

func (*Writer) Buffered 

func (w *Writer) Buffered() int

Buffered returns the number of buffered bytes.

func (*Writer) Flush 

func (w *Writer) Flush() error

Flush writes any buffered data to the underlying io.Writer.

func (*Writer) Reset 

func (w *Writer) Reset(out io.Writer)

Reset resets the Writer with a new io.Writer attached.

func (*Writer) Write 

func (w *Writer) Write(b []byte) (int, error)

Write writes raw bytes to the Writer.

func (*Writer) WriteBlockCB 

func (w *Writer) WriteBlockCB(callback func(w *Writer) int64) int64

WriteBlockCB writes a block using the callback.

func (*Writer) WriteBlockHeader 

func (w *Writer) WriteBlockHeader(l, s int64)

WriteBlockHeader writes a Block Header to the Writer.

func (*Writer) WriteBool 

func (w *Writer) WriteBool(b bool)

WriteBool writes a Bool to the Writer.

func (*Writer) WriteBytes 

func (w *Writer) WriteBytes(b []byte)

WriteBytes writes Bytes to the Writer.

func (*Writer) WriteDouble 

func (w *Writer) WriteDouble(f float64)

WriteDouble writes a Double to the Writer.

func (*Writer) WriteFloat 

func (w *Writer) WriteFloat(f float32)

WriteFloat writes a Float to the Writer.

func (*Writer) WriteInt 

func (w *Writer) WriteInt(i int32)

WriteInt writes an Int to the Writer.

func (*Writer) WriteLong 

func (w *Writer) WriteLong(i int64)

WriteLong writes a Long to the Writer.

func (*Writer) WriteString 

func (w *Writer) WriteString(s string)

WriteString reads a String to the Writer.

func (*Writer) WriteVal 

func (w *Writer) WriteVal(schema Schema, val interface{})

WriteVal writes the Avro encoding of obj.

type WriterFunc 

type WriterFunc func(w *Writer)

WriterFunc is a function used to customize the Writer.

func WithWriterConfig 

func WithWriterConfig(cfg API) WriterFunc

WithWriterConfig specifies the configuration to use with a writer.

Source Files

View all Source files

Directories

Path Synopsis
cmd
avrogen
Package gen allows generating Go structs from avro schemas.
 Package gen allows generating Go structs from avro schemas.
internal
bytesx
Package bytesx implements bytes extensions.
 Package bytesx implements bytes extensions.
Package ocf implements encoding and decoding of Avro Object Container Files as defined by the Avro specification.
 Package ocf implements encoding and decoding of Avro Object Container Files as defined by the Avro specification.
pkg
crc64
Package crc64 implements the Avro CRC-64 checksum.
 Package crc64 implements the Avro CRC-64 checksum.
Package registry implements a Confluent Schema Registry compliant client.
 Package registry implements a Confluent Schema Registry compliant client.

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