[experiment] add alternative wasm sqlite3 implementation available via build-tag (#2863)

This allows for building GoToSocial with [SQLite transpiled to WASM](https://github.com/ncruces/go-sqlite3) and accessed through [Wazero](https://wazero.io/).

1 files changed, 96 insertions, 0 deletions

diff --git a/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/wazevoapi/perfmap.go b/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/wazevoapi/perfmap.go
new file mode 100644
index 000000000..642c7f75d
--- /dev/null
+++ b/vendor/github.com/tetratelabs/wazero/internal/engine/wazevo/wazevoapi/perfmap.go
@@ -0,0 +1,96 @@
+package wazevoapi
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"sync"
+)
+
+var PerfMap *Perfmap
+
+func init() {
+	if PerfMapEnabled {
+		pid := os.Getpid()
+		filename := "/tmp/perf-" + strconv.Itoa(pid) + ".map"
+
+		fh, err := os.OpenFile(filename, os.O_APPEND|os.O_RDWR|os.O_CREATE, 0o644)
+		if err != nil {
+			panic(err)
+		}
+
+		PerfMap = &Perfmap{fh: fh}
+	}
+}
+
+// Perfmap holds perfmap entries to be flushed into a perfmap file.
+type Perfmap struct {
+	entries []entry
+	mux     sync.Mutex
+	fh      *os.File
+}
+
+type entry struct {
+	index  int
+	offset int64
+	size   uint64
+	name   string
+}
+
+func (f *Perfmap) Lock() {
+	f.mux.Lock()
+}
+
+func (f *Perfmap) Unlock() {
+	f.mux.Unlock()
+}
+
+// AddModuleEntry adds a perfmap entry into the perfmap file.
+// index is the index of the function in the module, offset is the offset of the function in the module,
+// size is the size of the function, and name is the name of the function.
+//
+// Note that the entries are not flushed into the perfmap file until Flush is called,
+// and the entries are module-scoped; Perfmap must be locked until Flush is called.
+func (f *Perfmap) AddModuleEntry(index int, offset int64, size uint64, name string) {
+	e := entry{index: index, offset: offset, size: size, name: name}
+	if f.entries == nil {
+		f.entries = []entry{e}
+		return
+	}
+	f.entries = append(f.entries, e)
+}
+
+// Flush writes the perfmap entries into the perfmap file where the entries are adjusted by the given `addr` and `functionOffsets`.
+func (f *Perfmap) Flush(addr uintptr, functionOffsets []int) {
+	defer func() {
+		_ = f.fh.Sync()
+	}()
+
+	for _, e := range f.entries {
+		if _, err := f.fh.WriteString(fmt.Sprintf("%x %s %s\n",
+			uintptr(e.offset)+addr+uintptr(functionOffsets[e.index]),
+			strconv.FormatUint(e.size, 16),
+			e.name,
+		)); err != nil {
+			panic(err)
+		}
+	}
+	f.entries = f.entries[:0]
+}
+
+// Clear clears the perfmap entries not yet flushed.
+func (f *Perfmap) Clear() {
+	f.entries = f.entries[:0]
+}
+
+// AddEntry writes a perfmap entry directly into the perfmap file, not using the entries.
+func (f *Perfmap) AddEntry(addr uintptr, size uint64, name string) {
+	_, err := f.fh.WriteString(fmt.Sprintf("%x %s %s\n",
+		addr,
+		strconv.FormatUint(size, 16),
+		name,
+	))
+	if err != nil {
+		panic(err)
+	}
+}