graph-gophers/graphql-go
Graphql Go
graphql-go is a schema-first GraphQL library and server implementation for Go. It provides a query execution engine and schema parser that converts schema definition strings into executable structures and validates resolver signatures. The library also includes a streaming implementation for real-time GraphQL subscriptions using channels within resolvers.
The project distinguishes itself through parallel resolver execution to reduce request latency and the use of buffer-pool memory management to lower garbage collection overhead. It enables the creation of cloneable schema instances from a shared syntax tree to apply unique resolver configurations or overrides.
The library covers broad capability areas including schema management with custom scalar definitions and metadata export, and security via query depth and complexity limitations. It also provides tools for efficient data fetching through selection-set inspection to prevent N+1 queries, as well as observability via execution tracing and resolver panic handling.
Features
- Query Execution Engines - Provides the core execution engine that evaluates GraphQL queries against a parsed schema to return structured data.
- Schema Parsers - Converts GraphQL schema definition strings into abstract syntax trees for validation and programmatic inspection.
- Resolver Method Mapping - Maps schema fields to exported methods or struct fields based on name matching for data retrieval.
- Abstract Syntax Tree Parsing - Converts GraphQL schema definition strings into abstract syntax trees to validate resolver signatures and structures.
- GraphQL API Implementations - Provides a full implementation of a server-side GraphQL interface to process queries and return structured data.
- Field Argument Handling - Parses query arguments into structured data types, scalars, and enums for use within field resolvers.
- Schema-First Development Frameworks - Provides a schema-first framework that uses the SDL as the source of truth for executable structure.
- GraphQL Schema Management - Provides tools for defining custom scalars, managing schemas, and exporting metadata for compatibility.
- GraphQL Schema Parsing - Implements the core mechanism to convert schema definition strings into executable structures and validate resolver signatures.
- GraphQL Servers - Provides a complete server-side implementation for parsing schemas and executing queries against resolvers.
- GraphQL Subscriptions - Implements server-side GraphQL subscriptions to stream real-time data updates to clients.
- Name-Based Field Resolvers - Automatically maps GraphQL schema fields to methods with matching names on the source resolver objects.
- Real-Time Data Streaming - Implements application-level streaming to push live server-side data updates to connected clients via GraphQL.
- Query Field Projections - Analyzes requested fields to optimize database projections and prevent over-fetching of data.
- Data Fetching Optimizations - Implements prefetching and batching strategies by inspecting requested fields to minimize database round-trips.
- Custom Scalars - Supports the definition of non-standard primitive data types through custom marshaling and unmarshaling logic.
- Schema Instance Cloning - Allows creating cloneable schema instances from a shared syntax tree to apply unique resolver configurations.
- Schema-to-Struct Mappings - Automatically maps internal Go struct fields to the GraphQL schema to serve as resolvers.
- Memory Allocation Optimizations - Reduces garbage collection overhead by reusing internal temporary buffers and managing memory pools during execution.
- GraphQL Query Complexity Protection - Protects server resources by restricting query execution based on character length or calculated complexity.
- GraphQL Security - Protects GraphQL APIs from resource exhaustion by limiting query depth and complexity.
- Query Complexity Protections - The GraphQL library caps the number of overlapping field combinations in a single query to prevent resource exhaustion.
- Query Depth Restrictions - Protects server resources by calculating and limiting the maximum nesting level of GraphQL queries.
- Schema Introspection Restrictions - Filters access to internal schema metadata via custom functions to prevent unauthorized discovery of the API structure.
- Resolver Channels - Implements real-time updates by returning Go channels from resolvers to stream multiple events to clients.
- Parallel Resolver Execution - Executes multiple field resolvers in parallel to reduce the total latency of a single query request.
- Reusable Buffer Pools - Utilizes reusable buffer pools to reduce memory allocation overhead and garbage collection pressure during query execution.
- N+1 Query Prevention - Inspects requested child fields to enable prefetching and batching, eliminating inefficient repeated database calls.
- Concurrent Resolver Execution - Executes multiple field resolvers concurrently to reduce the total latency of a single query request.
- Resolver Coverage Validation - Verifies that all required resolver methods are implemented by the provided types during system initialization.
- Selection Set Inspection - Analyzes requested fields within the resolver context to optimize database projections and avoid over-fetching.
- Query Languages - GraphQL server implementation.
- Go GraphQL Tools - Go server library focused on ease of use.
