graphql.c File Reference

#include <cwist/net/graphql/graphql.h>
#include <cwist/core/mem/alloc.h>
#include <cwist/core/sstring/sstring.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>

Include dependency graph for graphql.c:

Go to the source code of this file.

Typedefs
typedef struct graphql_field	graphql_field_t

Enumerations
enum	gql_op_type_t { GQL_OP_QUERY , GQL_OP_MUTATION }

Functions
cwist_graphql_schema_t *	cwist_graphql_schema_create (void)
	Allocate an empty GraphQL schema with no query or mutation fields.
void	cwist_graphql_schema_destroy (cwist_graphql_schema_t *schema)
	Destroy a schema and all registered query/mutation fields.
bool	cwist_graphql_add_query (cwist_graphql_schema_t *schema, const char *field, cwist_graphql_resolver_fn resolver, void *ctx)
	Register a resolver for a GraphQL query field.
bool	cwist_graphql_add_mutation (cwist_graphql_schema_t *schema, const char *field, cwist_graphql_resolver_fn resolver, void *ctx)
	Register a resolver for a GraphQL mutation field.
cwist_error_t	cwist_graphql_execute (cwist_graphql_schema_t *schema, const char *request_json, cwist_sstring **out_json)
	Execute a GraphQL query or mutation from a JSON request body.
bool	cwist_graphql_parse_subscription (const char *query, const cJSON *variables, char *field_out, size_t field_cap, cJSON **args_out)
	Extract the root field name and parsed arguments of a subscription operation.
void	cwist_graphql_serve (cwist_graphql_schema_t *schema, cwist_http_request *req, cwist_http_response *res)
	HTTP handler serving GraphQL requests over POST.

Typedef Documentation

graphql_field_t

typedef struct graphql_field graphql_field_t

Enumeration Type Documentation

gql_op_type_t

enum gql_op_type_t

Enumerator
GQL_OP_QUERY
GQL_OP_MUTATION

Definition at line 9 of file graphql.c.

Function Documentation

cwist_graphql_add_mutation()

bool cwist_graphql_add_mutation	(	cwist_graphql_schema_t *	schema,
		const char *	field,
		cwist_graphql_resolver_fn	resolver,
		void *	ctx
	)

Register a resolver for a GraphQL mutation field.

Parameters

schema	Schema to register the field on.
field	Mutation field name (must be a valid GraphQL name).
resolver	Resolver callback invoked when the field is mutated.
ctx	Opaque pointer passed to the resolver.

Return values

true	The field was registered (or its resolver updated).
false	NULL schema or invalid field/resolver.

Definition at line 172 of file graphql.c.

References cap.

cwist_graphql_add_query()

bool cwist_graphql_add_query	(	cwist_graphql_schema_t *	schema,
		const char *	field,
		cwist_graphql_resolver_fn	resolver,
		void *	ctx
	)

Register a resolver for a GraphQL query field.

Parameters

schema	Schema to register the field on.
field	Query field name (must be a valid GraphQL name).
resolver	Resolver callback invoked when the field is queried.
ctx	Opaque pointer passed to the resolver.

Return values

true	The field was registered (or its resolver updated).
false	NULL schema or invalid field/resolver.

Definition at line 157 of file graphql.c.

References cap.

cwist_graphql_execute()

cwist_error_t cwist_graphql_execute	(	cwist_graphql_schema_t *	schema,
		const char *	request_json,
		cwist_sstring **	out_json
	)

Execute a GraphQL query or mutation from a JSON request body.

The request must be a JSON object with a string "query" member and an optional "variables" object. On success *out_json receives a compact JSON response of the form {"data": {...}} with an "errors" array added when resolution produced errors. Ownership of *out_json transfers to the caller.

Parameters

schema	Schema providing the query/mutation fields.
request_json	JSON-encoded GraphQL request text.
out_json	Receives the response body string on success.

Returns

0 on success, non-zero on invalid arguments or internal failure.

Definition at line 467 of file graphql.c.

References cap, CWIST_GRAPHQL_MAX_QUERY_SIZE, cwist_sstring_assign(), cwist_sstring_create(), GQL_OP_MUTATION, and GQL_OP_QUERY.

Referenced by cwist_graphql_serve().

cwist_graphql_parse_subscription()

bool cwist_graphql_parse_subscription	(	const char *	query,
		const cJSON *	variables,
		char *	field_out,
		size_t	field_cap,
		cJSON **	args_out
	)

Extract the root field name and parsed arguments of a subscription operation.

Used by the experimental WS subscription layer (cwist/net/graphql/graphql_ws.h); not part of the query/mutation execute path. Only the first root field is reported, matching the single-stream model of the graphql-ws broker.

Parameters

query	GraphQL subscription query text.
variables	Optional cJSON object of variable values.
field_out	Buffer receiving the resolved root field name.
field_cap	Capacity of field_out in bytes.
args_out	Receives a newly allocated cJSON argument object (NULL when the field carries no arguments); caller owns it.

Return values

true	The subscription field and arguments were extracted.
false	Invalid arguments or malformed subscription query.

Definition at line 557 of file graphql.c.

References cap.

cwist_graphql_schema_create()

cwist_graphql_schema_t * cwist_graphql_schema_create

(

void

)

Allocate an empty GraphQL schema with no query or mutation fields.

Returns

Newly allocated schema on success, NULL on allocation failure. The caller owns the result and must free it with cwist_graphql_schema_destroy().

Definition at line 79 of file graphql.c.

References cap, and cwist_alloc().

cwist_graphql_schema_destroy()

void cwist_graphql_schema_destroy

(

cwist_graphql_schema_t *

schema

)

Destroy a schema and all registered query/mutation fields.

Parameters

schema

Schema to free (may be NULL).

Definition at line 105 of file graphql.c.

References cwist_free().

cwist_graphql_serve()

void cwist_graphql_serve	(	cwist_graphql_schema_t *	schema,
		cwist_http_request *	req,
		cwist_http_response *	res
	)

HTTP handler serving GraphQL requests over POST.

Executes the request body via cwist_graphql_execute() and writes the JSON response. Non-POST requests or execution failures yield a 400 status with an error body. The Content-Type header is always set to application/json.

Parameters

schema	Schema used to resolve the request.
req	Incoming HTTP request (must use POST).
res	Response object receiving status, body, and headers.

Definition at line 618 of file graphql.c.

References cwist_http_request::body, cwist_http_response::body, cap, cwist_graphql_execute(), CWIST_HTTP_BAD_REQUEST, cwist_http_header_add(), CWIST_HTTP_OK, CWIST_HTTP_POST, cwist_sstring_assign(), cwist_sstring_assign_len(), cwist_sstring_destroy(), cwist_sstring::data, cwist_http_response::headers, cwist_http_request::method, cwist_sstring::size, and cwist_http_response::status_code.