1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3  * License, v. 2.0. If a copy of the MPL was not distributed with this
4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5 
6 // This file provides substitutes for the basic stdio routines used by hyphen.c
7 // to read its dictionary files. We #define the stdio names to these versions
8 // in hnjalloc.h, so that we can use nsIURI and nsIInputStream to specify and
9 // access the dictionary resources.
10 
11 #include "hnjalloc.h"
12 #undef FILE // Undo the damage done in hnjalloc.h
13 #include "nsNetUtil.h"
14 #include "nsIInputStream.h"
15 #include "nsIURI.h"
16 #include "nsContentUtils.h"
17 
18 #define BUFSIZE 1024
19 
20 struct hnjFile_ {
21     nsCOMPtr<nsIInputStream> mStream;
22     char                     mBuffer[BUFSIZE];
23     uint32_t                 mCurPos;
24     uint32_t                 mLimit;
25 };
26 
27 // replacement for fopen()
28 // (not a full substitute: only supports read access)
29 hnjFile*
30 hnjFopen(const char* aURISpec, const char* aMode)
31 {
32     // this override only needs to support "r"
33     NS_ASSERTION(!strcmp(aMode, "r"), "unsupported fopen() mode in hnjFopen");
34 
35     nsCOMPtr<nsIURI> uri;
36     nsresult rv = NS_NewURI(getter_AddRefs(uri), aURISpec);
37     if (NS_FAILED(rv)) {
38         return nullptr;
39     }
40 
41     nsCOMPtr<nsIChannel> channel;
42     rv = NS_NewChannel(getter_AddRefs(channel),
43                        uri,
44                        nsContentUtils::GetSystemPrincipal(),
45                        nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_DATA_IS_NULL,
46                        nsIContentPolicy::TYPE_OTHER);
47     if (NS_FAILED(rv)) {
48         return nullptr;
49     }
50 
51     nsCOMPtr<nsIInputStream> instream;
52     rv = channel->Open2(getter_AddRefs(instream));
53     if (NS_FAILED(rv)) {
54         return nullptr;
55     }
56 
57     hnjFile *f = new hnjFile;
58     f->mStream = instream;
59     f->mCurPos = 0;
60     f->mLimit = 0;
61 
62     return f;
63 }
64 
65 // replacement for fclose()
66 int
67 hnjFclose(hnjFile* f)
68 {
69     NS_ASSERTION(f && f->mStream, "bad argument to hnjFclose");
70 
71     int result = 0;
72     nsresult rv = f->mStream->Close();
73     if (NS_FAILED(rv)) {
74         result = EOF;
75     }
76     f->mStream = nullptr;
77 
78     delete f;
79     return result;
80 }
81 
82 // replacement for fgets()
83 // (not a full reimplementation, but sufficient for libhyphen's needs)
84 char*
85 hnjFgets(char* s, int n, hnjFile* f)
86 {
87     NS_ASSERTION(s && f, "bad argument to hnjFgets");
88 
89     int i = 0;
90     while (i < n - 1) {
91         if (f->mCurPos < f->mLimit) {
92             char c = f->mBuffer[f->mCurPos++];
93             s[i++] = c;
94             if (c == '\n' || c == '\r') {
95                 break;
96             }
97             continue;
98         }
99 
100         f->mCurPos = 0;
101 
102         nsresult rv = f->mStream->Read(f->mBuffer, BUFSIZE, &f->mLimit);
103         if (NS_FAILED(rv)) {
104             f->mLimit = 0;
105             return nullptr;
106         }
107 
108         if (f->mLimit == 0) {
109             break;
110         }
111     }
112 
113     if (i == 0) {
114         return nullptr; // end of file
115     }
116 
117     s[i] = '\0'; // null-terminate the returned string
118     return s;
119 }
120