From cce21232cc83060a53ecb3a7c30d7f6fbfd7a529 Mon Sep 17 00:00:00 2001
From: Charlie Stanton <charlie@shtanton.xyz>
Date: Tue, 25 Apr 2023 09:56:00 +0100
Subject: Now uses a buffered output for writing to improve performance
---
main/main.go | 3 ++-
walk/walk.go | 41 ++++++++++++++++++++++-------------------
2 files changed, 24 insertions(+), 20 deletions(-)
diff --git a/main/main.go b/main/main.go
index e6730de..0c7324b 100644
--- a/main/main.go
+++ b/main/main.go
@@ -40,10 +40,11 @@ func main() {
program := Parse(tokens)
stdin := bufio.NewReader(os.Stdin)
+ stdout := bufio.NewWriter(os.Stdout)
state := ProgramState {
in: walk.NewJSONIn(stdin),
- out: walk.NewJSONOut(),
+ out: walk.NewJSONOut(stdout),
program: program,
}
diff --git a/walk/walk.go b/walk/walk.go
index 0719d1c..f9bac2a 100644
--- a/walk/walk.go
+++ b/walk/walk.go
@@ -511,10 +511,11 @@ const (
type JSONOut struct {
structure []JSONOutStructure
+ writer *bufio.Writer
}
func (out *JSONOut) indent(adjust int) {
- fmt.Print(strings.Repeat("\t", len(out.structure) - 1 + adjust))
+ fmt.Fprint(out.writer, strings.Repeat("\t", len(out.structure) - 1 + adjust))
}
func (out *JSONOut) atomOut(key string, atom Atom) {
@@ -525,46 +526,46 @@ func (out *JSONOut) atomOut(key string, atom Atom) {
case AtomNull, AtomBool, AtomNumber:
out.indent(0)
if state == JSONOutMap {
- fmt.Printf("%q: ", key)
+ fmt.Fprintf(out.writer, "%q: ", key)
}
- fmt.Print(atom.String())
+ fmt.Fprint(out.writer, atom.String())
out.structure = append(out.structure, JSONOutValueEnd)
case AtomStringTerminal:
out.indent(0)
if state == JSONOutMap {
- fmt.Printf("%q: ", key)
+ fmt.Fprintf(out.writer, "%q: ", key)
}
- fmt.Print("\"")
+ fmt.Fprint(out.writer, "\"")
out.structure = append(out.structure, JSONOutString)
case AtomTerminal:
switch TerminalValue(atom.data) {
case MapBegin:
out.indent(0)
if state == JSONOutMap {
- fmt.Printf("%q: ", key)
+ fmt.Fprintf(out.writer, "%q: ", key)
}
- fmt.Print("{\n")
+ fmt.Fprint(out.writer, "{\n")
out.structure = append(out.structure, JSONOutMap)
case ArrayBegin:
out.indent(0)
if state == JSONOutMap {
- fmt.Printf("%q: ", key)
+ fmt.Fprintf(out.writer, "%q: ", key)
}
- fmt.Print("[\n")
+ fmt.Fprint(out.writer, "[\n")
out.structure = append(out.structure, JSONOutArray)
case MapEnd:
out.indent(-1)
if state != JSONOutMap {
panic("Map ended while not inside a map")
}
- fmt.Print("}")
+ fmt.Fprint(out.writer, "}")
out.structure[len(out.structure) - 1] = JSONOutValueEnd
case ArrayEnd:
out.indent(-1)
if state != JSONOutArray {
panic("Array ended while not inside a array")
}
- fmt.Print("]")
+ fmt.Fprint(out.writer, "]")
out.structure[len(out.structure) - 1] = JSONOutValueEnd
default:
panic("Invalid TerminalValue")
@@ -576,27 +577,27 @@ func (out *JSONOut) atomOut(key string, atom Atom) {
out.structure = out.structure[:len(out.structure) - 1]
underState := out.structure[len(out.structure) - 1]
if underState == JSONOutMap && atom.Typ == AtomTerminal && TerminalValue(atom.data) == MapEnd {
- fmt.Print("\n")
+ fmt.Fprint(out.writer, "\n")
out.indent(-1)
- fmt.Print("}")
+ fmt.Fprint(out.writer, "}")
out.structure[len(out.structure) - 1] = JSONOutValueEnd
} else if underState == JSONOutArray && atom.Typ == AtomTerminal && TerminalValue(atom.data) == ArrayEnd {
- fmt.Print("\n")
+ fmt.Fprint(out.writer, "\n")
out.indent(-1)
- fmt.Print("]")
+ fmt.Fprint(out.writer, "]")
out.structure[len(out.structure) - 1] = JSONOutValueEnd
} else if underState == JSONOutRoot {
panic("Tried to output JSON after root value has concluded")
} else {
- fmt.Print(",\n")
+ fmt.Fprint(out.writer, ",\n")
out.atomOut(key, atom)
}
case JSONOutString:
if atom.Typ == AtomStringTerminal {
- fmt.Print("\"")
+ fmt.Fprint(out.writer, "\"")
out.structure[len(out.structure) - 1] = JSONOutValueEnd
} else {
- fmt.Print(atom.String())
+ fmt.Fprint(out.writer, atom.String())
}
default:
panic("Invalid JSONOutState")
@@ -615,14 +616,16 @@ func (out *JSONOut) Print(path Path, values []Atom) {
}
func (out *JSONOut) AssertDone() {
+ out.writer.Flush()
if len(out.structure) != 2 || out.structure[0] != JSONOutRoot || out.structure[1] != JSONOutValueEnd {
panic("Program ended with incomplete JSON output")
}
}
-func NewJSONOut() JSONOut {
+func NewJSONOut(writer *bufio.Writer) JSONOut {
return JSONOut {
structure: []JSONOutStructure{JSONOutRoot},
+ writer: writer,
}
}
--
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