A fork of Gitea (see branch `mj`) adding Majority Judgment Polls 𐄷 over Issues and Merge Requests. https://git.mieuxvoter.fr
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// Copyright 2020 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package gitgraph
import (
"bytes"
"fmt"
)
// Parser represents a git graph parser. It is stateful containing the previous
// glyphs, detected flows and color assignments.
type Parser struct {
glyphs []byte
oldGlyphs []byte
flows []int64
oldFlows []int64
maxFlow int64
colors []int
oldColors []int
availableColors []int
nextAvailable int
firstInUse int
firstAvailable int
maxAllowedColors int
}
// Reset resets the internal parser state.
func (parser *Parser) Reset() {
parser.glyphs = parser.glyphs[0:0]
parser.oldGlyphs = parser.oldGlyphs[0:0]
parser.flows = parser.flows[0:0]
parser.oldFlows = parser.oldFlows[0:0]
parser.maxFlow = 0
parser.colors = parser.colors[0:0]
parser.oldColors = parser.oldColors[0:0]
parser.availableColors = parser.availableColors[0:0]
parser.availableColors = append(parser.availableColors, 1, 2)
parser.nextAvailable = 0
parser.firstInUse = -1
parser.firstAvailable = 0
parser.maxAllowedColors = 0
}
// AddLineToGraph adds the line as a row to the graph
func (parser *Parser) AddLineToGraph(graph *Graph, row int, line []byte) error {
idx := bytes.Index(line, []byte("DATA:"))
if idx < 0 {
parser.ParseGlyphs(line)
} else {
parser.ParseGlyphs(line[:idx])
}
var err error
commitDone := false
for column, glyph := range parser.glyphs {
if glyph == ' ' {
continue
}
flowID := parser.flows[column]
graph.AddGlyph(row, column, flowID, parser.colors[column], glyph)
if glyph == '*' {
if commitDone {
if err != nil {
err = fmt.Errorf("double commit on line %d: %s. %w", row, string(line), err)
} else {
err = fmt.Errorf("double commit on line %d: %s", row, string(line))
}
}
commitDone = true
if idx < 0 {
if err != nil {
err = fmt.Errorf("missing data section on line %d with commit: %s. %w", row, string(line), err)
} else {
err = fmt.Errorf("missing data section on line %d with commit: %s", row, string(line))
}
continue
}
err2 := graph.AddCommit(row, column, flowID, line[idx+5:])
if err != nil && err2 != nil {
err = fmt.Errorf("%v %w", err2, err)
continue
} else if err2 != nil {
err = err2
continue
}
}
}
if !commitDone {
graph.Commits = append(graph.Commits, RelationCommit)
}
return err
}
func (parser *Parser) releaseUnusedColors() {
if parser.firstInUse > -1 {
// Here we step through the old colors, searching for them in the
// "in-use" section of availableColors (that is, the colors between
// firstInUse and firstAvailable)
// Ensure that the benchmarks are not worsened with proposed changes
stepstaken := 0
position := parser.firstInUse
for _, color := range parser.oldColors {
if color == 0 {
continue
}
found := false
i := position
for j := stepstaken; i != parser.firstAvailable && j < len(parser.availableColors); j++ {
colorToCheck := parser.availableColors[i]
if colorToCheck == color {
found = true
break
}
i = (i + 1) % len(parser.availableColors)
}
if !found {
// Duplicate color
continue
}
// Swap them around
parser.availableColors[position], parser.availableColors[i] = parser.availableColors[i], parser.availableColors[position]
stepstaken++
position = (parser.firstInUse + stepstaken) % len(parser.availableColors)
if position == parser.firstAvailable || stepstaken == len(parser.availableColors) {
break
}
}
if stepstaken == len(parser.availableColors) {
parser.firstAvailable = -1
} else {
parser.firstAvailable = position
if parser.nextAvailable == -1 {
parser.nextAvailable = parser.firstAvailable
}
}
}
}
// ParseGlyphs parses the provided glyphs and sets the internal state
func (parser *Parser) ParseGlyphs(glyphs []byte) {
// Clean state for parsing this row
parser.glyphs, parser.oldGlyphs = parser.oldGlyphs, parser.glyphs
parser.glyphs = parser.glyphs[0:0]
parser.flows, parser.oldFlows = parser.oldFlows, parser.flows
parser.flows = parser.flows[0:0]
parser.colors, parser.oldColors = parser.oldColors, parser.colors
// Ensure we have enough flows and colors
parser.colors = parser.colors[0:0]
for range glyphs {
parser.flows = append(parser.flows, 0)
parser.colors = append(parser.colors, 0)
}
// Copy the provided glyphs in to state.glyphs for safekeeping
parser.glyphs = append(parser.glyphs, glyphs...)
// release unused colors
parser.releaseUnusedColors()
for i := len(glyphs) - 1; i >= 0; i-- {
glyph := glyphs[i]
switch glyph {
case '|':
fallthrough
case '*':
parser.setUpFlow(i)
case '/':
parser.setOutFlow(i)
case '\\':
parser.setInFlow(i)
case '_':
parser.setRightFlow(i)
case '.':
fallthrough
case '-':
parser.setLeftFlow(i)
case ' ':
// no-op
default:
parser.newFlow(i)
}
}
}
func (parser *Parser) takePreviousFlow(i, j int) {
if j < len(parser.oldFlows) && parser.oldFlows[j] > 0 {
parser.flows[i] = parser.oldFlows[j]
parser.oldFlows[j] = 0
parser.colors[i] = parser.oldColors[j]
parser.oldColors[j] = 0
} else {
parser.newFlow(i)
}
}
func (parser *Parser) takeCurrentFlow(i, j int) {
if j < len(parser.flows) && parser.flows[j] > 0 {
parser.flows[i] = parser.flows[j]
parser.colors[i] = parser.colors[j]
} else {
parser.newFlow(i)
}
}
func (parser *Parser) newFlow(i int) {
parser.maxFlow++
parser.flows[i] = parser.maxFlow
// Now give this flow a color
if parser.nextAvailable == -1 {
next := len(parser.availableColors)
if parser.maxAllowedColors < 1 || next < parser.maxAllowedColors {
parser.nextAvailable = next
parser.firstAvailable = next
parser.availableColors = append(parser.availableColors, next+1)
}
}
parser.colors[i] = parser.availableColors[parser.nextAvailable]
if parser.firstInUse == -1 {
parser.firstInUse = parser.nextAvailable
}
parser.availableColors[parser.firstAvailable], parser.availableColors[parser.nextAvailable] = parser.availableColors[parser.nextAvailable], parser.availableColors[parser.firstAvailable]
parser.nextAvailable = (parser.nextAvailable + 1) % len(parser.availableColors)
parser.firstAvailable = (parser.firstAvailable + 1) % len(parser.availableColors)
if parser.nextAvailable == parser.firstInUse {
parser.nextAvailable = parser.firstAvailable
}
if parser.nextAvailable == parser.firstInUse {
parser.nextAvailable = -1
parser.firstAvailable = -1
}
}
// setUpFlow handles '|' or '*'
func (parser *Parser) setUpFlow(i int) {
// In preference order:
//
// Previous Row: '\? ' ' |' ' /'
// Current Row: ' | ' ' |' ' | '
if i > 0 && i-1 < len(parser.oldGlyphs) && parser.oldGlyphs[i-1] == '\\' {
parser.takePreviousFlow(i, i-1)
} else if i < len(parser.oldGlyphs) && (parser.oldGlyphs[i] == '|' || parser.oldGlyphs[i] == '*') {
parser.takePreviousFlow(i, i)
} else if i+1 < len(parser.oldGlyphs) && parser.oldGlyphs[i+1] == '/' {
parser.takePreviousFlow(i, i+1)
} else {
parser.newFlow(i)
}
}
// setOutFlow handles '/'
func (parser *Parser) setOutFlow(i int) {
// In preference order:
//
// Previous Row: ' |/' ' |_' ' |' ' /' ' _' '\'
// Current Row: '/| ' '/| ' '/ ' '/ ' '/ ' '/'
if i+2 < len(parser.oldGlyphs) &&
(parser.oldGlyphs[i+1] == '|' || parser.oldGlyphs[i+1] == '*') &&
(parser.oldGlyphs[i+2] == '/' || parser.oldGlyphs[i+2] == '_') &&
i+1 < len(parser.glyphs) &&
(parser.glyphs[i+1] == '|' || parser.glyphs[i+1] == '*') {
parser.takePreviousFlow(i, i+2)
} else if i+1 < len(parser.oldGlyphs) &&
(parser.oldGlyphs[i+1] == '|' || parser.oldGlyphs[i+1] == '*' ||
parser.oldGlyphs[i+1] == '/' || parser.oldGlyphs[i+1] == '_') {
parser.takePreviousFlow(i, i+1)
if parser.oldGlyphs[i+1] == '/' {
parser.glyphs[i] = '|'
}
} else if i < len(parser.oldGlyphs) && parser.oldGlyphs[i] == '\\' {
parser.takePreviousFlow(i, i)
} else {
parser.newFlow(i)
}
}
// setInFlow handles '\'
func (parser *Parser) setInFlow(i int) {
// In preference order:
//
// Previous Row: '| ' '-. ' '| ' '\ ' '/' '---'
// Current Row: '|\' ' \' ' \' ' \' '\' ' \ '
if i > 0 && i-1 < len(parser.oldGlyphs) &&
(parser.oldGlyphs[i-1] == '|' || parser.oldGlyphs[i-1] == '*') &&
(parser.glyphs[i-1] == '|' || parser.glyphs[i-1] == '*') {
parser.newFlow(i)
} else if i > 0 && i-1 < len(parser.oldGlyphs) &&
(parser.oldGlyphs[i-1] == '|' || parser.oldGlyphs[i-1] == '*' ||
parser.oldGlyphs[i-1] == '.' || parser.oldGlyphs[i-1] == '\\') {
parser.takePreviousFlow(i, i-1)
if parser.oldGlyphs[i-1] == '\\' {
parser.glyphs[i] = '|'
}
} else if i < len(parser.oldGlyphs) && parser.oldGlyphs[i] == '/' {
parser.takePreviousFlow(i, i)
} else {
parser.newFlow(i)
}
}
// setRightFlow handles '_'
func (parser *Parser) setRightFlow(i int) {
// In preference order:
//
// Current Row: '__' '_/' '_|_' '_|/'
if i+1 < len(parser.glyphs) &&
(parser.glyphs[i+1] == '_' || parser.glyphs[i+1] == '/') {
parser.takeCurrentFlow(i, i+1)
} else if i+2 < len(parser.glyphs) &&
(parser.glyphs[i+1] == '|' || parser.glyphs[i+1] == '*') &&
(parser.glyphs[i+2] == '_' || parser.glyphs[i+2] == '/') {
parser.takeCurrentFlow(i, i+2)
} else {
parser.newFlow(i)
}
}
// setLeftFlow handles '----.'
func (parser *Parser) setLeftFlow(i int) {
if parser.glyphs[i] == '.' {
parser.newFlow(i)
} else if i+1 < len(parser.glyphs) &&
(parser.glyphs[i+1] == '-' || parser.glyphs[i+1] == '.') {
parser.takeCurrentFlow(i, i+1)
} else {
parser.newFlow(i)
}
}