wasm: simplify platform-specific page size handling

Replace os.Getpagesize() calls with common.DefaultPageSize constant and remove redundant pagesize.go implementation. Simplify WASM-specific code by removing custom initialization and page size handling. Update tests to use the new constant.

Signed-off-by: Travis Cline <[email protected]>

Author: tmc

db.go

@@ -784,11 +784,13 @@ func (db *DB) beginTx() (*Tx, error) {
 	// write transaction will obtain them.
 	db.metalock.Lock()
 
-	// Allow platform-specific transaction initialization
-	if initer, ok := any(db).(txIniter); ok {
-		if err := initer.txInit(); err != nil {
-			db.metalock.Unlock()
-			return nil, err
+	// Allow WASM-specific transaction initialization
+	if runtime.GOARCH == "wasm" {
+		if initer, ok := any(db).(txIniter); ok {
+			if err := initer.txInit(); err != nil {
+				db.metalock.Unlock()
+				return nil, err
+			}
 		}
 	}
 
@@ -849,11 +851,13 @@ func (db *DB) beginRWTx() (*Tx, error) {
 	db.metalock.Lock()
 	defer db.metalock.Unlock()
 
-	// Allow platform-specific transaction initialization
-	if initer, ok := any(db).(txIniter); ok {
-		if err := initer.txInit(); err != nil {
-			db.rwlock.Unlock()
-			return nil, err
+	// Allow WASM-specific transaction initialization
+	if runtime.GOARCH == "wasm" {
+		if initer, ok := any(db).(txIniter); ok {
+			if err := initer.txInit(); err != nil {
+				db.rwlock.Unlock()
+				return nil, err
+			}
 		}
 	}
 

db_test.go

@@ -24,7 +24,6 @@ import (
 	bolt "go.etcd.io/bbolt"
 	berrors "go.etcd.io/bbolt/errors"
 	"go.etcd.io/bbolt/internal/btesting"
-	"go.etcd.io/bbolt/internal/common"
 )
 
 // pageSize is the size of one page in the data file.
@@ -241,7 +240,7 @@ func TestOpen_ReadPageSize_FromMeta1_OS(t *testing.T) {
 
 	// Reopen data file.
 	db = btesting.MustOpenDBWithOption(t, path, nil)
-	require.Equalf(t, common.GetPagesize(), db.Info().PageSize, "check page size failed")
+	require.Equalf(t, os.Getpagesize(), db.Info().PageSize, "check page size failed")
 }
 
 // Ensure that it can read the page size from the second meta page if the first one is invalid.

internal/common/bolt_wasm.go

@@ -3,22 +3,7 @@
 package common
 
 // MaxMapSize represents the largest mmap size supported by Bolt.
-// Reduced for WASM due to memory constraints.
-const MaxMapSize = 0x10000000 // 256MB
+const MaxMapSize = 0x10000000
 
 // MaxAllocSize is the size used when creating array pointers.
-// Slightly larger than MaxMapSize to accommodate metadata overhead.
-const MaxAllocSize = 0x10100000 // 257MB
-
-func init() {
-	// Override the default page size for WASM to use 4KB instead of 64KB.
-	// This reduces memory usage and makes behavior more consistent with other platforms.
-	// Note: Databases created with different page sizes are not compatible.
-	DefaultPageSize = 4096
-}
-
-// GetPagesize returns the system page size.
-// On WASM platforms, we always return 4KB as the page size.
-func GetPagesize() int {
-	return 4096
-}
+const MaxAllocSize = 0x10100000