From b0c414a3426c26d98df4f205f3707397eb5671e9 Mon Sep 17 00:00:00 2001
From: Piotr Jastrzebski <piotr@chiselstrike.com>
Date: Thu, 18 Jul 2024 13:26:42 +0200
Subject: [PATCH 1/2] Optimize arguments handling

Remove memory/cpu overhead of handling arguments when they are empty.
This is important in case of user loading a dump of their database.
In such a case, there are no arguments at all and the number of
statements is usually big.

When testing on a 650M sql file this change reduces number of total
allocation from 122772583kB to 38511376 so ~69%.

Signed-off-by: Piotr Jastrzebski <piotr@chiselstrike.com>
---
 libsql/internal/hrana/stream_request.go  | 15 ++++++++++-----
 libsql/internal/http/hranaV2/hranaV2.go  |  6 +++++-
 libsql/internal/http/shared/statement.go |  7 +++++--
 3 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/libsql/internal/hrana/stream_request.go b/libsql/internal/hrana/stream_request.go
index 0b00dc4..a47b077 100644
--- a/libsql/internal/hrana/stream_request.go
+++ b/libsql/internal/hrana/stream_request.go
@@ -16,13 +16,15 @@ func CloseStream() StreamRequest {
 	return StreamRequest{Type: "close"}
 }
 
-func ExecuteStream(sql string, params shared.Params, wantRows bool) (*StreamRequest, error) {
+func ExecuteStream(sql string, params *shared.Params, wantRows bool) (*StreamRequest, error) {
 	stmt := &Stmt{
 		Sql:      &sql,
 		WantRows: wantRows,
 	}
-	if err := stmt.AddArgs(params); err != nil {
-		return nil, err
+	if params != nil {
+		if err := stmt.AddArgs(*params); err != nil {
+			return nil, err
+		}
 	}
 	return &StreamRequest{Type: "execute", Stmt: stmt}, nil
 }
@@ -40,14 +42,17 @@ func ExecuteStoredStream(sqlId int32, params shared.Params, wantRows bool) (*Str
 
 func BatchStream(sqls []string, params []shared.Params, wantRows bool, transactional bool) (*StreamRequest, error) {
 	batch := &Batch{}
+	addArgs := len(params) > 0
 	for idx, sql := range sqls {
 		s := sql
 		stmt := &Stmt{
 			Sql:      &s,
 			WantRows: wantRows,
 		}
-		if err := stmt.AddArgs(params[idx]); err != nil {
-			return nil, err
+		if addArgs {
+			if err := stmt.AddArgs(params[idx]); err != nil {
+				return nil, err
+			}
 		}
 		var condition *BatchCondition
 		if transactional {
diff --git a/libsql/internal/http/hranaV2/hranaV2.go b/libsql/internal/http/hranaV2/hranaV2.go
index 1ce4831..6c79014 100644
--- a/libsql/internal/http/hranaV2/hranaV2.go
+++ b/libsql/internal/http/hranaV2/hranaV2.go
@@ -293,7 +293,11 @@ func (h *hranaV2Conn) executeStmt(ctx context.Context, query string, args []driv
 	}
 	msg := &hrana.PipelineRequest{}
 	if len(stmts) == 1 {
-		executeStream, err := hrana.ExecuteStream(stmts[0], params[0], wantRows)
+		var p *shared.Params
+		if len(params) > 0 {
+			p = &params[0]
+		}
+		executeStream, err := hrana.ExecuteStream(stmts[0], p, wantRows)
 		if err != nil {
 			return nil, fmt.Errorf("failed to execute SQL: %s\n%w", query, err)
 		}
diff --git a/libsql/internal/http/shared/statement.go b/libsql/internal/http/shared/statement.go
index ce44055..584a5fc 100644
--- a/libsql/internal/http/shared/statement.go
+++ b/libsql/internal/http/shared/statement.go
@@ -32,13 +32,16 @@ func ParseStatement(sql string) ([]string, []ParamsInfo, error) {
 }
 
 func ParseStatementAndArgs(sql string, args []driver.NamedValue) ([]string, []Params, error) {
+	stmts, _ := sqliteparserutils.SplitStatement(sql)
+
+	if len(args) == 0 {
+		return stmts, nil, nil
+	}
 	parameters, err := ConvertArgs(args)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	stmts, _ := sqliteparserutils.SplitStatement(sql)
-
 	stmtsParams := make([]Params, len(stmts))
 	totalParametersAlreadyUsed := 0
 	for idx, stmt := range stmts {

From bd6bb5bee66c13a3715d5be6d606abefb1284123 Mon Sep 17 00:00:00 2001
From: Piotr Jastrzebski <piotr@chiselstrike.com>
Date: Thu, 18 Jul 2024 14:00:54 +0200
Subject: [PATCH 2/2] Reserve enough space when creating batch

This reduces number of allocations during batch creation from
5636431kB to 1679694kB which is ~70%.

Signed-off-by: Piotr Jastrzebski <piotr@chiselstrike.com>
---
 libsql/internal/hrana/stream_request.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/libsql/internal/hrana/stream_request.go b/libsql/internal/hrana/stream_request.go
index a47b077..caea86b 100644
--- a/libsql/internal/hrana/stream_request.go
+++ b/libsql/internal/hrana/stream_request.go
@@ -41,7 +41,11 @@ func ExecuteStoredStream(sqlId int32, params shared.Params, wantRows bool) (*Str
 }
 
 func BatchStream(sqls []string, params []shared.Params, wantRows bool, transactional bool) (*StreamRequest, error) {
-	batch := &Batch{}
+	size := len(sqls)
+	if transactional {
+		size += 1
+	}
+	batch := &Batch{Steps: make([]BatchStep, 0, size)}
 	addArgs := len(params) > 0
 	for idx, sql := range sqls {
 		s := sql