feat(analyzer): Cache query analysis

When using managed databases, cache the query analysis if the query, schema and configuration file hasn't change. Also take into account the version of sqlc. Analysis can only be cached for managed databases as we can't know if a connected database has been changed.
sqlc-dev · kyleconroy · Oct 20, 2023 · Oct 19, 2023 · Oct 19, 2023 · Oct 20, 2023
commit 32996a2f381b3c38051e39c8836273807f960494
diff --git a/internal/analyzer/analyzer.go b/internal/analyzer/analyzer.go
@@ -2,45 +2,95 @@ package analyzer
 
 import (
 	"context"
+	"fmt"
+	"hash/fnv"
+	"os"
+	"path/filepath"
 
+	"google.golang.org/protobuf/proto"
+
+	"github.com/sqlc-dev/sqlc/internal/analyzer/pb"
+	"github.com/sqlc-dev/sqlc/internal/cache"
+	"github.com/sqlc-dev/sqlc/internal/config"
+	"github.com/sqlc-dev/sqlc/internal/info"
 	"github.com/sqlc-dev/sqlc/internal/sql/ast"
 	"github.com/sqlc-dev/sqlc/internal/sql/named"
 )
 
-type Column struct {
-	Name         string
-	OriginalName string
-	DataType     string
-	NotNull      bool
-	Unsigned     bool
-	IsArray      bool
-	ArrayDims    int
-	Comment      string
-	Length       *int
-	IsNamedParam bool
-	IsFuncCall   bool
-
-	// XXX: Figure out what PostgreSQL calls `foo.id`
-	Scope      string
-	Table      *ast.TableName
-	TableAlias string
-	Type       *ast.TypeName
-	EmbedTable *ast.TableName
-
-	IsSqlcSlice bool // is this sqlc.slice()
+type CachedAnalyzer struct {
+	a          Analyzer
+	configPath string
+	config     []byte
+	db         config.Database
+}
+
+func Cached(a Analyzer, cp string, db config.Database) *CachedAnalyzer {
+	return &CachedAnalyzer{
+		a:          a,
+		configPath: cp,
+		db:         db,
+	}
 }
 
-type Parameter struct {
-	Number int
-	Column *Column
+func (c *CachedAnalyzer) Analyze(ctx context.Context, n ast.Node, q string, schema []string, np *named.ParamSet) (*pb.Analysis, error) {
+	// Only cache queries for managed databases. We can't be certain the the
+	// database is in an unchanged state otherwise
+	if !c.db.Managed {
+		return c.a.Analyze(ctx, n, q, schema, np)
+	}
+
+	dir, err := cache.AnalysisDir()
+	if err != nil {
+		return nil, err
+	}
+
+	if c.config == nil {
+		c.config, err = os.ReadFile(c.configPath)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	// Calculate cache key
+	h := fnv.New64()
+	h.Write([]byte(info.Version))
+	h.Write(c.config)
+	for _, m := range schema {
+		h.Write([]byte(m))
+	}
+	h.Write([]byte(q))
+
+	key := fmt.Sprintf("%x", h.Sum(nil))
+	path := filepath.Join(dir, key)
+	if _, err := os.Stat(path); err == nil {
+		contents, err := os.ReadFile(path)
+		if err != nil {
+			return nil, err
+		}
+		var a pb.Analysis
+		return &a, proto.Unmarshal(contents, &a)
+	}
+
+	result, err := c.a.Analyze(ctx, n, q, schema, np)
+
+	if err == nil {
+		contents, err := proto.Marshal(result)
+		if err != nil {
+			return nil, err
+		}
+		if err := os.WriteFile(path, contents, 0644); err != nil {
+			return nil, err
+		}
+	}
+
+	return result, err
 }
 
-type Analysis struct {
-	Columns []Column
-	Params  []Parameter
+func (c *CachedAnalyzer) Close(ctx context.Context) error {
+	return c.a.Close(ctx)
 }
 
 type Analyzer interface {
-	Analyze(context.Context, ast.Node, string, []string, *named.ParamSet) (*Analysis, error)
+	Analyze(context.Context, ast.Node, string, []string, *named.ParamSet) (*pb.Analysis, error)
 	Close(context.Context) error
 }