use the same struct for all schema access

Unify the struct used for Schemes and GetProviderSchemaResponse so that
we can have a single cache which handles all schema access.

internal/providers/provider.go

@@ -6,6 +6,7 @@ package providers
 import (
 	"github.com/zclconf/go-cty/cty"
 
+	"github.com/hashicorp/terraform/internal/configs/configschema"
 	"github.com/hashicorp/terraform/internal/states"
 	"github.com/hashicorp/terraform/internal/tfdiags"
 )
@@ -73,13 +74,6 @@ type Interface interface {
 	Close() error
 }
 
-// All access to a provider's schema internally should bt through the Schemas
-// type.
-// TODO: Acccess to schemas was split over two types with slightly different
-// structures in different parts of the code. These types need to be unified
-// for easier and more consistent access, but there is however a large amount
-// of code which directly uses this structure, so it is not easily refactored
-// out.
 type GetProviderSchemaResponse struct {
 	// Provider is the schema for the provider itself.
 	Provider Schema
@@ -100,6 +94,17 @@ type GetProviderSchemaResponse struct {
 	ServerCapabilities ServerCapabilities
 }
 
+// Schema pairs a provider or resource schema with that schema's version.
+// This is used to be able to upgrade the schema in UpgradeResourceState.
+//
+// This describes the schema for a single object within a provider. Type
+// "Schemas" (plural) instead represents the overall collection of schemas
+// for everything within a particular provider.
+type Schema struct {
+	Version int64
+	Block   *configschema.Block
+}
+
 // ServerCapabilities allows providers to communicate extra information
 // regarding supported protocol features. This is used to indicate availability
 // of certain forward-compatible changes which may be optional in a major

internal/providers/schema_cache.go

@@ -9,11 +9,11 @@ import (
 	"github.com/hashicorp/terraform/internal/addrs"
 )
 
-// SchemaCache is a global cache of GetProviderSchemaResponses.
+// SchemaCache is a global cache of Schemas.
 // This will be accessed by both core and the provider clients to ensure that
 // large schemas are stored in a single location.
 var SchemaCache = &schemaCache{
-	m: make(map[addrs.Provider]GetProviderSchemaResponse),
+	m: make(map[addrs.Provider]Schemas),
 }
 
 // Global cache for provider schemas
@@ -22,17 +22,17 @@ var SchemaCache = &schemaCache{
 // concurrent calls resulting in an error can be handled in the same manner.
 type schemaCache struct {
 	mu sync.Mutex
-	m  map[addrs.Provider]GetProviderSchemaResponse
+	m  map[addrs.Provider]Schemas
 }
 
-func (c *schemaCache) Set(p addrs.Provider, s GetProviderSchemaResponse) {
+func (c *schemaCache) Set(p addrs.Provider, s Schemas) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 
 	c.m[p] = s
 }
 
-func (c *schemaCache) Get(p addrs.Provider) (GetProviderSchemaResponse, bool) {
+func (c *schemaCache) Get(p addrs.Provider) (Schemas, bool) {
 	c.mu.Lock()
 	defer c.mu.Unlock()
 

internal/providers/schemas.go

@@ -6,49 +6,22 @@ package providers
 import (
 	"github.com/hashicorp/terraform/internal/addrs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
-	"github.com/hashicorp/terraform/internal/tfdiags"
 )
 
 // Schemas is an overall container for all of the schemas for all configurable
 // objects defined within a particular provider.
-//
+type Schemas = GetProviderSchemaResponse
-// The schema for each individual configurable object is represented by nested
-// instances of type Schema (singular) within this data structure.
-type Schemas struct {
-	// Provider is the schema for the provider itself.
-	Provider *configschema.Block
-
-	// ProviderMeta is the schema for the provider's meta info in a module
-	ProviderMeta *configschema.Block
-
-	// ResourceTypes map the resource type name to that type's schema.
-	ResourceTypes              map[string]*configschema.Block
-	ResourceTypeSchemaVersions map[string]uint64
-
-	// DataSources maps the data source name to that data source's schema.
-	DataSources map[string]*configschema.Block
-
-	// ServerCapabilities lists optional features supported by the provider.
-	ServerCapabilities ServerCapabilities
-
-	// Diagnostics contains any warnings or errors from the method call.
-	// While diagnostics are only relevant to the initial call, we add these to
-	// the cached structure so that concurrent calls can handle failures
-	// gracefully when the original call did not succeed.
-	// TODO: can we be sure the original failure get handled correctly, and
-	// ignore this entirely?
-	Diagnostics tfdiags.Diagnostics
-}
 
 // SchemaForResourceType attempts to find a schema for the given mode and type.
 // Returns nil if no such schema is available.
-func (ss *Schemas) SchemaForResourceType(mode addrs.ResourceMode, typeName string) (schema *configschema.Block, version uint64) {
+func (ss Schemas) SchemaForResourceType(mode addrs.ResourceMode, typeName string) (schema *configschema.Block, version uint64) {
 	switch mode {
 	case addrs.ManagedResourceMode:
-		return ss.ResourceTypes[typeName], ss.ResourceTypeSchemaVersions[typeName]
+		res := ss.ResourceTypes[typeName]
+		return res.Block, uint64(res.Version)
 	case addrs.DataResourceMode:
 		// Data resources don't have schema versions right now, since state is discarded for each refresh
-		return ss.DataSources[typeName], 0
+		return ss.DataSources[typeName].Block, 0
 	default:
 		// Shouldn't happen, because the above cases are comprehensive.
 		return nil, 0
@@ -57,41 +30,6 @@ func (ss *Schemas) SchemaForResourceType(mode addrs.ResourceMode, typeName strin
 
 // SchemaForResourceAddr attempts to find a schema for the mode and type from
 // the given resource address. Returns nil if no such schema is available.
-func (ss *Schemas) SchemaForResourceAddr(addr addrs.Resource) (schema *configschema.Block, version uint64) {
+func (ss Schemas) SchemaForResourceAddr(addr addrs.Resource) (schema *configschema.Block, version uint64) {
 	return ss.SchemaForResourceType(addr.Mode, addr.Type)
 }
-
-func SchemaResponseToSchemas(resp GetProviderSchemaResponse) *Schemas {
-	var schemas = &Schemas{
-		ResourceTypes:              make(map[string]*configschema.Block),
-		ResourceTypeSchemaVersions: make(map[string]uint64),
-		DataSources:                make(map[string]*configschema.Block),
-		ServerCapabilities:         resp.ServerCapabilities,
-		Diagnostics:                resp.Diagnostics,
-	}
-
-	schemas.Provider = resp.Provider.Block
-	schemas.ProviderMeta = resp.ProviderMeta.Block
-
-	for name, res := range resp.ResourceTypes {
-		schemas.ResourceTypes[name] = res.Block
-		schemas.ResourceTypeSchemaVersions[name] = uint64(res.Version)
-	}
-
-	for name, dat := range resp.DataSources {
-		schemas.DataSources[name] = dat.Block
-	}
-
-	return schemas
-}
-
-// Schema pairs a provider or resource schema with that schema's version.
-// This is used to be able to upgrade the schema in UpgradeResourceState.
-//
-// This describes the schema for a single object within a provider. Type
-// "Schemas" (plural) instead represents the overall collection of schemas
-// for everything within a particular provider.
-type Schema struct {
-	Version int64
-	Block   *configschema.Block
-}