1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
|
package commands
import (
"bufio"
"bytes"
"fmt"
"io"
"os"
"path"
"sync"
"git.sr.ht/~rjarry/aerc/log"
"github.com/kyoh86/xdg"
)
type cmdHistory struct {
// rolling buffer of prior commands
//
// most recent command is at the end of the list,
// least recent is index 0
cmdList []string
// current placement in list
current int
// initialize history storage
initHistfile sync.Once
histfile io.ReadWriter
}
// number of commands to keep in history
const cmdLimit = 1000
// CmdHistory is the history of executed commands
var CmdHistory = cmdHistory{}
func (h *cmdHistory) Add(cmd string) {
h.initHistfile.Do(h.initialize)
// if we're at cap, cut off the first element
if len(h.cmdList) >= cmdLimit {
h.cmdList = h.cmdList[1:]
}
if len(h.cmdList) == 0 || h.cmdList[len(h.cmdList)-1] != cmd {
h.cmdList = append(h.cmdList, cmd)
h.writeHistory()
}
// whenever we add a new command, reset the current
// pointer to the "beginning" of the list
h.Reset()
}
// Prev returns the previous command in history.
// Since the list is reverse-order, this will return elements
// increasingly towards index 0.
func (h *cmdHistory) Prev() string {
h.initHistfile.Do(h.initialize)
if h.current <= 0 || len(h.cmdList) == 0 {
h.current = -1
return "(Already at beginning)"
}
h.current--
return h.cmdList[h.current]
}
// Next returns the next command in history.
// Since the list is reverse-order, this will return elements
// increasingly towards index len(cmdList).
func (h *cmdHistory) Next() string {
h.initHistfile.Do(h.initialize)
if h.current >= len(h.cmdList)-1 || len(h.cmdList) == 0 {
h.current = len(h.cmdList)
return "(Already at end)"
}
h.current++
return h.cmdList[h.current]
}
// Reset the current pointer to the beginning of history.
func (h *cmdHistory) Reset() {
h.current = len(h.cmdList)
}
func (h *cmdHistory) initialize() {
var err error
openFlags := os.O_RDWR | os.O_EXCL
histPath := path.Join(xdg.CacheHome(), "aerc", "history")
if _, err := os.Stat(histPath); os.IsNotExist(err) {
_ = os.MkdirAll(path.Join(xdg.CacheHome(), "aerc"), 0o700) // caught by OpenFile
openFlags |= os.O_CREATE
}
// O_EXCL to make sure that only one aerc writes to the file
h.histfile, err = os.OpenFile(
histPath,
openFlags,
0o600,
)
if err != nil {
log.Errorf("failed to open history file: %v", err)
// basically mirror the old behavior
h.histfile = bytes.NewBuffer([]byte{})
return
}
s := bufio.NewScanner(h.histfile)
for s.Scan() {
h.cmdList = append(h.cmdList, s.Text())
}
h.Reset()
}
func (h *cmdHistory) writeHistory() {
if fh, ok := h.histfile.(*os.File); ok {
err := fh.Truncate(0)
if err != nil {
// if we can't delete it, don't break it.
return
}
_, err = fh.Seek(0, io.SeekStart)
if err != nil {
// if we can't delete it, don't break it.
return
}
for _, entry := range h.cmdList {
fmt.Fprintln(fh, entry)
}
fh.Sync() //nolint:errcheck // if your computer can't sync you're in bigger trouble
}
}
|
