eg https://github.com/vektah/gqlparser/blob/f21cb62205146978875c90e1fff0e3043c848235/parser/query.go#L169 will need to be
&FragmentSpread
I need to visit all SelectionSet and it has Definitions (e.g. Field with FieldDefinition)
- All sub nodes have Definition too
- InlineFragment's fields...
- FragmentSpread's fields...
- deeply nested foobar's fields...
↓
How can the above be achieved?
I tried below code.
observers := w.Observers
w.Observers = &Events{}
w.walk()
w.Observers = observers
w.walk()However, there were a lot of code call by value and the value was still nil.
(and It's a bit inefficient.)
↓
Do I have to use function arguments as pointers?
It is necessary to change to the following code.
for idx := range w.Document.Operations {
child := &w.Document.Operations[idx]
w.validatedFragmentSpreads = make(map[string]bool)
w.walkOperation(child)
}and... Selection seems difficult unless we change the definition.
Writing as usual would do as follows.
This is a confusing bug that values are ghostly eaten.
This is a confusing bug that values are ghostly eaten.
for _, child := range w.Document.Operations {
w.validatedFragmentSpreads = make(map[string]bool)
w.walkOperation(&child)
}right, so because
type QueryDocument struct {
Operations []OperationDefinition
}operations is all allocated contiguously in memory (its very efficient to loop over due to cache coherency, but adding elements can be costly)
Operations: [OperationDefinition(Operation: "query", Name: "", ...)][OperationDefinition(Operation: "query", Name: "", ...)][OperationDefinition(Operation: "query", Name: "", ...)]the problem is a for loop copies it when traversing:
for i, def := range document.Operation {
// &def is a pointer to a copy
// &document.Operation[i] is a pointer to the element of the array
}wheras if
type QueryDocument struct {
Operations []*OperationDefinition // note pointer
}you end up with an array of pointers, referencing objects randomly allocated all over the place
op 3: [OperationDefinition(Operation: "query", Name: "", ...)]
[ptr to 1][ptr to 2][ptr to 3]
op 1: [OperationDefinition(Operation: "query", Name: "", ...)]
op 2: [OperationDefinition(Operation: "query", Name: "", ...)]when you loop over the pointers, go still copies them, but its a copy of a pointer so it doesnt matter so much, the cost you pay is now your reading things from random locations in memory as you loop, which is much slower if you do it a lot (for operation it probably doesnt matter, you expect a few items max
feel free to make []*things wherever you need, we can always wind them back to []things if they are expected to be lager
pretty sure contiguous arrays are also less pressure on the gc, not having to clean up lots of small references. perf without benchmarks is dumb though, so do what makes sense
:D
vektah/gqlparser#39 makes all the collections []*Thing
@vektah I have a question.
https://github.com/vektah/gqlparser/blob/master/spec/validation/deviations.yml#L13-L26
Why these tests are marked
https://github.com/vektah/gqlparser/blob/master/spec/validation/deviations.yml#L13-L26
Why these tests are marked
skip: true ?
we should try and get them implemented
https://github.com/graph-gophers/graphql-go/blob/master/internal/validation/testdata/export.js#L76-L111 ftr they have lots of skips
amazing :heart_eyes:
I'm tracking stuff for "1.0" on https://github.com/vektah/gqlgen/projects/1, if you see something you want to work on feel free
just drag it into "in progress" so someone else doesn't start working on it
I think Mat will start to break down that directive card some more once he gets his head around how it will all hoook in
Have you looked into using https://github.com/graphql-go/graphql/tree/master/language parser instead of writing your own?
the parser and lexer are actually really easy
the validation is hard
also line count comparisons are interesting,
110 ./benchutil/list_schema.go
144 ./benchutil/wide_schema.go
1311 ./definition.go
148 ./directives.go
74 ./examples/context/main.go
141 ./examples/custom-scalar-type/main.go
41 ./examples/hello-world/main.go
114 ./examples/http/main.go
138 ./examples/httpdynamic/main.go
75 ./examples/modify-context/main.go
24 ./examples/star-wars/main.go
225 ./examples/todo/main.go
872 ./executor.go
78 ./gqlerrors/error.go
62 ./gqlerrors/formatted.go
39 ./gqlerrors/located.go
30 ./gqlerrors/sortutil.go
69 ./gqlerrors/syntax.go
63 ./graphql.go
763 ./introspection.go
29 ./language/ast/arguments.go
235 ./language/ast/definitions.go
33 ./language/ast/directives.go
31 ./language/ast/document.go
22 ./language/ast/location.go
28 ./language/ast/name.go
45 ./language/ast/node.go
134 ./language/ast/selections.go
103 ./language/ast/types.go
529 ./language/ast/type_definitions.go
302 ./language/ast/values.go
59 ./language/kinds/kinds.go
682 ./language/lexer/lexer.go
35 ./language/location/location.go
1607 ./language/parser/parser.go
822 ./language/printer/printer.go
20 ./language/source/source.go
11 ./language/typeInfo/type_info.go
736 ./language/visitor/visitor.go
51 ./located.go
1892 ./rules.go
706 ./rules_overlapping_fields_can_be_merged.go
433 ./scalars.go
538 ./schema.go
99 ./testutil/introspection_query.go
622 ./testutil/rules_test_harness.go
468 ./testutil/testutil.go
16 ./types.go
276 ./type_info.go
192 ./util.go
287 ./validator.go
421 ./values.go
15985 totalvs
138 ./ast/collections.go
92 ./ast/definition.go
38 ./ast/directive.go
65 ./ast/document.go
159 ./ast/dumper.go
38 ./ast/fragment.go
29 ./ast/operation.go
35 ./ast/selection.go
14 ./ast/source.go
68 ./ast/type.go
115 ./ast/value.go
88 ./gqlerror/error.go
35 ./gqlparser.go
58 ./lexer/blockstring.go
510 ./lexer/lexer.go
148 ./lexer/token.go
112 ./parser/parser.go
334 ./parser/query.go
503 ./parser/schema.go
138 ./parser/testrunner/runner.go
55 ./validator/error.go
30 ./validator/inliner/inliner.go
39 ./validator/messaging.go
5 ./validator/prelude.go
86 ./validator/rules/fields_on_correct_type.go
39 ./validator/rules/fragments_on_composite_types.go
57 ./validator/rules/known_argument_names.go
31 ./validator/rules/known_directives.go
19 ./validator/rules/known_fragment_names.go
61 ./validator/rules/known_type_names.go
19 ./validator/rules/lone_anonymous_operation.go
93 ./validator/rules/no_fragment_cycles.go
28 ./validator/rules/no_undefined_variables.go
30 ./validator/rules/no_unused_fragments.go
30 ./validator/rules/no_unused_variables.go
553 ./validator/rules/overlapping_fields_can_be_merged.go
68 ./validator/rules/possible_fragment_spreads.go
63 ./validator/rules/provided_required_arguments.go
36 ./validator/rules/scalar_leafs.go
30 ./validator/rules/single_field_subscriptions.go
33 ./validator/rules/unique_argument_names.go
24 ./validator/rules/unique_directives_per_location.go
22 ./validator/rules/unique_fragment_names.go
27 ./validator/rules/unique_input_field_names.go
22 ./validator/rules/unique_operation_names.go
23 ./validator/rules/unique_variable_names.go
130 ./validator/rules/values_of_correct_type.go
28 ./validator/rules/variables_are_input_types.go
36 ./validator/rules/variables_in_allowed_position.go
199 ./validator/schema.go
69 ./validator/suggestionList.go
44 ./validator/validator.go
286 ./validator/walk.go
5032 total
there was a lot in the last spec release https://github.com/facebook/graphql/releases
the old parser (https://github.com/graph-gophers/graphql-go/tree/master/internal) had fallen behind a fair bit
I have seen this sort of thing.
the implementation is pretty clean