cb7c24141a
This commit implements a reimagining of the way the btcjson package
functions based upon how the project has evolved and lessons learned while
using it since it was first written. It therefore contains significant
changes to the API. For now, it has been implemented in a v2 subdirectory
to prevent breaking existing callers, but the ultimate goal is to update
all callers to use the new version and then to replace the old API with
the new one.
This also removes the need for the btcws completely since those commands
have been rolled in.
The following is an overview of the changes and some reasoning behind why
they were made:
- The infrastructure has been completely changed to be reflection based instead
of requiring thousands and thousands of lines of manual, and therefore error
prone, marshal/unmarshal code
- This makes it much easier to add new commands without making marshalling
mistakes since it is simply a struct definition and a call to register that
new struct (plus a trivial New<foo>Cmd function and tests, of course)
- It also makes it much easier to gain a lot of information from simply
looking at the struct definition which was previously not possible
such as the order of the parameters, which parameters are required
versus optional, and what the default values for optional parameters
are
- Each command now has usage flags associated with them that can be
queried which are intended to allow classification of the commands such
as for chain server and wallet server and websocket-only
- The help infrastructure has been completely redone to provide automatic
generation with caller provided description map and result types. This
is in contrast to the previous method of providing the help directly
which meant it would end up in the binary of anything that imported the
package
- Many of the structs have been renamed to use the terminology from the
JSON-RPC
specification:
- RawCmd/Message is now only a single struct named Request to reflect the fact
it is a JSON-RPC request
- Error is now called RPCError to reflect the fact it is specifically an RPC
error as opposed to many of the other errors that are possible
- All RPC error codes except the standard JSON-RPC 2.0 errors have been
converted from full structs to only codes since an audit of the codebase
has shown that the messages are overridden the vast majority of the time
with specifics (as they should be) and removing them also avoids the
temptation to return non-specific, and therefore not as helpful, error
messages
- There is now an Error which provides a type assertable error with
error codes so callers can better ascertain failure reasons
programatically
- The ID is no longer a part of the command and is instead specified at the time
the command is marshalled into a JSON-RPC request. This aligns better with
the way JSON-RPC functions since it is the caller who manages the ID that is
sent with any given _request_, not the package
- All <Foo>Cmd structs now treat non-pointers as required fields and pointers as
optional fields
- All New<Foo>Cmd functions now accept the exact number of parameters, with
pointers to the appropriate type for optional parameters
- This is preferrable to the old vararg syntax since it means the code will
fail to compile if the optional arguments are changed now which helps
prevent errors creep in over time from missed modifications to optional args
- All of the connection related code has been completely eliminated since this
package is not intended to used a client, rather it is intended to provide
the infrastructure needed to marshal/unmarshal Bitcoin-specific JSON-RPC
requests and replies from static types
- The btcrpcclient package provides a robust client with connection management
and higher-level types that in turn uses the primitives provided by this
package
- Even if the caller does not wish to use btcrpcclient for some reason, they
should still be responsible for connection management since they might want
to use any number of connection features which the package would not
necessarily support
- Synced a few of the commands that have added new optional fields that
have since been added to Bitcoin Core
- Includes all of the commands and notifications that were previously in
btcws
- Now provides 100% test coverage with parallel tests
- The code is completely golint and go vet clean
This has the side effect of addressing nearly everything in, and therefore
closes #26.
Also fixes #18 and closes #19.
112 lines
3.6 KiB
Go
112 lines
3.6 KiB
Go
// Copyright (c) 2014 Conformal Systems LLC.
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package btcjson
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import (
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"fmt"
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)
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// ErrorCode identifies a kind of error. These error codes are NOT used for
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// JSON-RPC response errors.
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type ErrorCode int
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// These constants are used to identify a specific RuleError.
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const (
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// ErrDuplicateMethod indicates a command with the specified method
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// already exists.
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ErrDuplicateMethod ErrorCode = iota
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// ErrInvalidUsageFlags indicates one or more unrecognized flag bits
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// were specified.
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ErrInvalidUsageFlags
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// ErrInvalidType indicates a type was passed that is not the required
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// type.
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ErrInvalidType
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// ErrEmbeddedType indicates the provided command struct contains an
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// embedded type which is not not supported.
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ErrEmbeddedType
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// ErrUnexportedField indiciates the provided command struct contains an
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// unexported field which is not supported.
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ErrUnexportedField
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// ErrUnsupportedFieldType indicates the type of a field in the provided
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// command struct is not one of the supported types.
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ErrUnsupportedFieldType
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// ErrNonOptionalField indicates a non-optional field was specified
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// after an optional field.
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ErrNonOptionalField
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// ErrNonOptionalDefault indicates a 'jsonrpcdefault' struct tag was
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// specified for a non-optional field.
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ErrNonOptionalDefault
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// ErrMismatchedDefault indicates a 'jsonrpcdefault' struct tag contains
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// a value that doesn't match the type of the field.
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ErrMismatchedDefault
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// ErrUnregisteredMethod indicates a method was specified that has not
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// been registered.
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ErrUnregisteredMethod
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// ErrMissingDescription indicates a description required to generate
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// help is missing.
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ErrMissingDescription
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// ErrNumParams inidcates the number of params supplied do not
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// match the requirements of the associated command.
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ErrNumParams
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// numErrorCodes is the maximum error code number used in tests.
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numErrorCodes
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)
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// Map of ErrorCode values back to their constant names for pretty printing.
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var errorCodeStrings = map[ErrorCode]string{
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ErrDuplicateMethod: "ErrDuplicateMethod",
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ErrInvalidUsageFlags: "ErrInvalidUsageFlags",
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ErrInvalidType: "ErrInvalidType",
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ErrEmbeddedType: "ErrEmbeddedType",
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ErrUnexportedField: "ErrUnexportedField",
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ErrUnsupportedFieldType: "ErrUnsupportedFieldType",
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ErrNonOptionalField: "ErrNonOptionalField",
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ErrNonOptionalDefault: "ErrNonOptionalDefault",
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ErrMismatchedDefault: "ErrMismatchedDefault",
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ErrUnregisteredMethod: "ErrUnregisteredMethod",
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ErrMissingDescription: "ErrMissingDescription",
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ErrNumParams: "ErrNumParams",
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}
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// String returns the ErrorCode as a human-readable name.
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func (e ErrorCode) String() string {
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if s := errorCodeStrings[e]; s != "" {
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return s
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}
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return fmt.Sprintf("Unknown ErrorCode (%d)", int(e))
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}
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// Error identifies a general error. This differs from an RPCError in that this
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// error typically is used more by the consumers of the package as opposed to
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// RPCErrors which are intended to be returned to the client across the wire via
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// a JSON-RPC Response. The caller can use type assertions to determine the
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// specific error and access the ErrorCode field.
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type Error struct {
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ErrorCode ErrorCode // Describes the kind of error
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Description string // Human readable description of the issue
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}
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// Error satisfies the error interface and prints human-readable errors.
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func (e Error) Error() string {
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return e.Description
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}
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// makeError creates an Error given a set of arguments.
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func makeError(c ErrorCode, desc string) Error {
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return Error{ErrorCode: c, Description: desc}
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}
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