forked from ethereum/go-ethereum
-
Notifications
You must be signed in to change notification settings - Fork 5
/
package.go
139 lines (117 loc) · 3.15 KB
/
package.go
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
// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package common
import (
"archive/zip"
"encoding/json"
"fmt"
"io"
"io/ioutil"
"strings"
)
// Manifest object
//
// The manifest object holds all the relevant information supplied with the
// the manifest specified in the package
type Manifest struct {
Entry string
Height, Width int
}
// External package
//
// External package contains the main html file and manifest
type ExtPackage struct {
EntryHtml string
Manifest *Manifest
}
// Read file
//
// Read a given compressed file and returns the read bytes.
// Returns an error otherwise
func ReadFile(f *zip.File) ([]byte, error) {
rc, err := f.Open()
if err != nil {
return nil, err
}
defer rc.Close()
content, err := ioutil.ReadAll(rc)
if err != nil {
return nil, err
}
return content, nil
}
// Reads manifest
//
// Reads and returns a manifest object. Returns error otherwise
func ReadManifest(m []byte) (*Manifest, error) {
var manifest Manifest
dec := json.NewDecoder(strings.NewReader(string(m)))
if err := dec.Decode(&manifest); err == io.EOF {
} else if err != nil {
return nil, err
}
return &manifest, nil
}
// Find file in archive
//
// Returns the index of the given file name if it exists. -1 if file not found
func FindFileInArchive(fn string, files []*zip.File) (index int) {
index = -1
// Find the manifest first
for i, f := range files {
if f.Name == fn {
index = i
}
}
return
}
// Open package
//
// Opens a prepared ethereum package
// Reads the manifest file and determines file contents and returns and
// the external package.
func OpenPackage(fn string) (*ExtPackage, error) {
r, err := zip.OpenReader(fn)
if err != nil {
return nil, err
}
defer r.Close()
manifestIndex := FindFileInArchive("manifest.json", r.File)
if manifestIndex < 0 {
return nil, fmt.Errorf("No manifest file found in archive")
}
f, err := ReadFile(r.File[manifestIndex])
if err != nil {
return nil, err
}
manifest, err := ReadManifest(f)
if err != nil {
return nil, err
}
if manifest.Entry == "" {
return nil, fmt.Errorf("Entry file specified but appears to be empty: %s", manifest.Entry)
}
entryIndex := FindFileInArchive(manifest.Entry, r.File)
if entryIndex < 0 {
return nil, fmt.Errorf("Entry file not found: '%s'", manifest.Entry)
}
f, err = ReadFile(r.File[entryIndex])
if err != nil {
return nil, err
}
extPackage := &ExtPackage{string(f), manifest}
return extPackage, nil
}