Schema Caching For Request and Response Bodies

cache/cache.go

@@ -0,0 +1,26 @@
+// Copyright 2023 Princess B33f Heavy Industries / Dave Shanley
+// SPDX-License-Identifier: MIT
+
+package cache
+
+import (
+	"github.com/pb33f/libopenapi/datamodel/high/base"
+	"github.com/santhosh-tekuri/jsonschema/v6"
+)
+
+// SchemaCacheEntry holds a compiled schema and its intermediate representations.
+// This is stored in the cache to avoid re-rendering and re-compiling schemas on each request.
+type SchemaCacheEntry struct {
+	Schema         *base.Schema
+	RenderedInline []byte
+	RenderedJSON   []byte
+	CompiledSchema *jsonschema.Schema
+}
+
+// SchemaCache defines the interface for schema caching implementations.
+// The key is a [32]byte hash of the schema (from schema.GoLow().Hash()).
+type SchemaCache interface {
+	Load(key [32]byte) (*SchemaCacheEntry, bool)
+	Store(key [32]byte, value *SchemaCacheEntry)
+	Range(f func(key [32]byte, value *SchemaCacheEntry) bool)
+}

cache/cache_test.go

@@ -0,0 +1,308 @@
+// Copyright 2023 Princess B33f Heavy Industries / Dave Shanley
+// SPDX-License-Identifier: MIT
+
+package cache
+
+import (
+	"testing"
+
+	"github.com/pb33f/libopenapi/datamodel/high/base"
+	"github.com/santhosh-tekuri/jsonschema/v6"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewDefaultCache(t *testing.T) {
+	cache := NewDefaultCache()
+	assert.NotNil(t, cache)
+	assert.NotNil(t, cache.m)
+}
+
+func TestDefaultCache_StoreAndLoad(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Create a test schema cache entry
+	testSchema := &SchemaCacheEntry{
+		Schema:         &base.Schema{},
+		RenderedInline: []byte("rendered"),
+		RenderedJSON:   []byte(`{"type":"object"}`),
+		CompiledSchema: &jsonschema.Schema{},
+	}
+
+	// Create a test key (32-byte hash)
+	var key [32]byte
+	copy(key[:], []byte("test-schema-hash-12345678901234"))
+
+	// Store the schema
+	cache.Store(key, testSchema)
+
+	// Load the schema back
+	loaded, ok := cache.Load(key)
+	assert.True(t, ok, "Should find the cached schema")
+	require.NotNil(t, loaded)
+	assert.Equal(t, testSchema.RenderedInline, loaded.RenderedInline)
+	assert.Equal(t, testSchema.RenderedJSON, loaded.RenderedJSON)
+	assert.NotNil(t, loaded.CompiledSchema)
+}
+
+func TestDefaultCache_LoadMissing(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Try to load a key that doesn't exist
+	var key [32]byte
+	copy(key[:], []byte("nonexistent-key-12345678901234"))
+
+	loaded, ok := cache.Load(key)
+	assert.False(t, ok, "Should not find non-existent key")
+	assert.Nil(t, loaded)
+}
+
+func TestDefaultCache_LoadNilCache(t *testing.T) {
+	var cache *DefaultCache
+
+	var key [32]byte
+	loaded, ok := cache.Load(key)
+
+	assert.False(t, ok)
+	assert.Nil(t, loaded)
+}
+
+func TestDefaultCache_StoreNilCache(t *testing.T) {
+	var cache *DefaultCache
+
+	// Should not panic
+	var key [32]byte
+	cache.Store(key, &SchemaCacheEntry{})
+
+	// Verify nothing was stored (cache is nil)
+	assert.Nil(t, cache)
+}
+
+func TestDefaultCache_Range(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Store multiple entries
+	entries := make(map[[32]byte]*SchemaCacheEntry)
+	for i := 0; i < 5; i++ {
+		var key [32]byte
+		copy(key[:], []byte{byte(i)})
+
+		entry := &SchemaCacheEntry{
+			RenderedInline: []byte{byte(i)},
+			RenderedJSON:   []byte{byte(i)},
+		}
+		entries[key] = entry
+		cache.Store(key, entry)
+	}
+
+	// Range over all entries
+	count := 0
+	foundKeys := make(map[[32]byte]bool)
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		count++
+		foundKeys[key] = true
+
+		// Verify the value matches what we stored
+		expected, exists := entries[key]
+		assert.True(t, exists, "Key should exist in original entries")
+		assert.Equal(t, expected.RenderedInline, value.RenderedInline)
+		return true
+	})
+
+	assert.Equal(t, 5, count, "Should iterate over all 5 entries")
+	assert.Equal(t, 5, len(foundKeys), "Should find all 5 unique keys")
+}
+
+func TestDefaultCache_RangeEarlyTermination(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Store multiple entries
+	for i := 0; i < 10; i++ {
+		var key [32]byte
+		copy(key[:], []byte{byte(i)})
+		cache.Store(key, &SchemaCacheEntry{})
+	}
+
+	// Range but stop after 3 iterations
+	count := 0
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		count++
+		return count < 3 // Stop after 3
+	})
+
+	assert.Equal(t, 3, count, "Should stop after 3 iterations")
+}
+
+func TestDefaultCache_RangeNilCache(t *testing.T) {
+	var cache *DefaultCache
+
+	// Should not panic
+	called := false
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		called = true
+		return true
+	})
+
+	assert.False(t, called, "Callback should not be called on nil cache")
+}
+
+func TestDefaultCache_RangeEmpty(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Range over empty cache
+	count := 0
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		count++
+		return true
+	})
+
+	assert.Equal(t, 0, count, "Should not iterate over empty cache")
+}
+
+func TestDefaultCache_Overwrite(t *testing.T) {
+	cache := NewDefaultCache()
+
+	var key [32]byte
+	copy(key[:], []byte("test-key"))
+
+	// Store first value
+	first := &SchemaCacheEntry{
+		RenderedInline: []byte("first"),
+	}
+	cache.Store(key, first)
+
+	// Store second value with same key
+	second := &SchemaCacheEntry{
+		RenderedInline: []byte("second"),
+	}
+	cache.Store(key, second)
+
+	// Load should return the second value
+	loaded, ok := cache.Load(key)
+	assert.True(t, ok)
+	require.NotNil(t, loaded)
+	assert.Equal(t, []byte("second"), loaded.RenderedInline)
+}
+
+func TestDefaultCache_MultipleKeys(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Store with different keys
+	var key1, key2, key3 [32]byte
+	copy(key1[:], []byte("key1"))
+	copy(key2[:], []byte("key2"))
+	copy(key3[:], []byte("key3"))
+
+	cache.Store(key1, &SchemaCacheEntry{RenderedInline: []byte("value1")})
+	cache.Store(key2, &SchemaCacheEntry{RenderedInline: []byte("value2")})
+	cache.Store(key3, &SchemaCacheEntry{RenderedInline: []byte("value3")})
+
+	// Load each one
+	val1, ok1 := cache.Load(key1)
+	val2, ok2 := cache.Load(key2)
+	val3, ok3 := cache.Load(key3)
+
+	assert.True(t, ok1)
+	assert.True(t, ok2)
+	assert.True(t, ok3)
+
+	assert.Equal(t, []byte("value1"), val1.RenderedInline)
+	assert.Equal(t, []byte("value2"), val2.RenderedInline)
+	assert.Equal(t, []byte("value3"), val3.RenderedInline)
+}
+
+func TestDefaultCache_ThreadSafety(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Concurrent writes
+	done := make(chan bool, 10)
+	for i := 0; i < 10; i++ {
+		go func(val int) {
+			var key [32]byte
+			copy(key[:], []byte{byte(val)})
+			cache.Store(key, &SchemaCacheEntry{
+				RenderedInline: []byte{byte(val)},
+			})
+			done <- true
+		}(i)
+	}
+
+	// Wait for all writes
+	for i := 0; i < 10; i++ {
+		<-done
+	}
+
+	// Concurrent reads
+	for i := 0; i < 10; i++ {
+		go func(val int) {
+			var key [32]byte
+			copy(key[:], []byte{byte(val)})
+			loaded, ok := cache.Load(key)
+			assert.True(t, ok)
+			assert.NotNil(t, loaded)
+			done <- true
+		}(i)
+	}
+
+	// Wait for all reads
+	for i := 0; i < 10; i++ {
+		<-done
+	}
+
+	// Verify all entries exist
+	count := 0
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		count++
+		return true
+	})
+	assert.Equal(t, 10, count, "All entries should be present")
+}
+
+func TestSchemaCache_Fields(t *testing.T) {
+	// Test that SchemaCache properly holds all fields
+	schema := &base.Schema{}
+	compiled := &jsonschema.Schema{}
+
+	sc := &SchemaCacheEntry{
+		Schema:         schema,
+		RenderedInline: []byte("rendered"),
+		RenderedJSON:   []byte(`{"type":"object"}`),
+		CompiledSchema: compiled,
+	}
+
+	assert.Equal(t, schema, sc.Schema)
+	assert.Equal(t, []byte("rendered"), sc.RenderedInline)
+	assert.Equal(t, []byte(`{"type":"object"}`), sc.RenderedJSON)
+	assert.Equal(t, compiled, sc.CompiledSchema)
+}
+
+func TestDefaultCache_RangeWithInvalidTypes(t *testing.T) {
+	cache := NewDefaultCache()
+
+	// Manually insert invalid types into the underlying sync.Map to test defensive programming
+	// Store an entry with wrong key type
+	cache.m.Store("invalid-key-type", &SchemaCacheEntry{})
+
+	// Store an entry with wrong value type
+	var validKey [32]byte
+	copy(validKey[:], []byte{1})
+	cache.m.Store(validKey, "invalid-value-type")
+
+	// Store a valid entry
+	var validKey2 [32]byte
+	copy(validKey2[:], []byte{2})
+	validEntry := &SchemaCacheEntry{RenderedInline: []byte("valid")}
+	cache.Store(validKey2, validEntry)
+
+	// Range should skip invalid entries and only process valid ones
+	count := 0
+	var seenEntry *SchemaCacheEntry
+	cache.Range(func(key [32]byte, value *SchemaCacheEntry) bool {
+		count++
+		seenEntry = value
+		return true
+	})
+
+	assert.Equal(t, 1, count, "Should only process valid entry")
+	assert.Equal(t, validEntry, seenEntry, "Should see the valid entry")
+}

cache/default_cache.go

@@ -0,0 +1,54 @@
+package cache
+
+import "sync"
+
+// DefaultCache is the default cache implementation using sync.Map for thread-safe concurrent access.
+type DefaultCache struct {
+	m *sync.Map
+}
+
+var _ SchemaCache = &DefaultCache{}
+
+// NewDefaultCache creates a new DefaultCache with an initialized sync.Map.
+func NewDefaultCache() *DefaultCache {
+	return &DefaultCache{m: &sync.Map{}}
+}
+
+// Load retrieves a schema from the cache.
+func (c *DefaultCache) Load(key [32]byte) (*SchemaCacheEntry, bool) {
+	if c == nil || c.m == nil {
+		return nil, false
+	}
+	val, ok := c.m.Load(key)
+	if !ok {
+		return nil, false
+	}
+	schemaCache, ok := val.(*SchemaCacheEntry)
+	return schemaCache, ok
+}
+
+// Store saves a schema to the cache.
+func (c *DefaultCache) Store(key [32]byte, value *SchemaCacheEntry) {
+	if c == nil || c.m == nil {
+		return
+	}
+	c.m.Store(key, value)
+}
+
+// Range calls f for each entry in the cache (for testing/inspection).
+func (c *DefaultCache) Range(f func(key [32]byte, value *SchemaCacheEntry) bool) {
+	if c == nil || c.m == nil {
+		return
+	}
+	c.m.Range(func(k, v interface{}) bool {
+		key, ok := k.([32]byte)
+		if !ok {
+			return true
+		}
+		val, ok := v.(*SchemaCacheEntry)
+		if !ok {
+			return true
+		}
+		return f(key, val)
+	})
+}