Perceptual Color

iohandlerfactory.cpp
1// SPDX-FileCopyrightText: Lukas Sommer <sommerluk@gmail.com>
2// SPDX-License-Identifier: BSD-2-Clause OR MIT
3
4// Own headers
5// First the interface, which forces the header to be self-contained.
6#include "iohandlerfactory.h"
7
8#include "helpermath.h"
9#include <lcms2.h>
10#include <lcms2_plugin.h>
11#include <limits>
12#include <qdebug.h>
13#include <qfile.h>
14#include <qglobal.h>
15#include <qiodevice.h>
16#include <qstringliteral.h>
17
18#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
19#include <qiodevicebase.h>
20#endif
21
22namespace PerceptualColor
23{
24/** @internal
25 *
26 * @brief Read from file.
27 *
28 * @param iohandler The <tt>cmsIOHANDLER</tt> on which to operate
29 * @param Buffer Pointer to the buffer to which the data should be loaded
30 * @param size Size of the chucks that should be loaded
31 * @param count Number of elements that should be loaded
32 * @returns On success, <tt>count</tt> is returned. If failing (either
33 * because less elements have been read or because zero elements have
34 * been read), <tt>0</tt> is returned. */
35cmsUInt32Number IOHandlerFactory::read(cmsIOHANDLER *iohandler, void *Buffer, cmsUInt32Number size, cmsUInt32Number count)
36{
37 QFile *const myFile = static_cast<QFile *>(iohandler->stream);
38 const cmsUInt32Number numberOfBytesRequested = size * count;
39 const qint64 numberOfBytesRead = myFile->read( //
40 static_cast<char *>(Buffer),
41 size * count);
42 if (numberOfBytesRead != numberOfBytesRequested) {
43 return 0;
44 }
45 return count;
46}
47
48/** @internal
49 *
50 * @brief Sets the current position within the file.
51 *
52 * @param iohandler The <tt>cmsIOHANDLER</tt> on which to operate
53 * @param offset Set the current position to this position
54 * @returns <tt>true</tt> on success, or <tt>false</tt> if an error
55 * occurred. */
56cmsBool IOHandlerFactory::seek(cmsIOHANDLER *iohandler, cmsUInt32Number offset)
57{
58 QFile *const myFile = static_cast<QFile *>(iohandler->stream);
59 const bool seekSucceeded = myFile->seek(offset);
60 if (!seekSucceeded) {
61 qDebug() << QStringLiteral("Seek error; probably corrupted file");
62 return false;
63 }
64 return true;
65}
66
67/** @internal
68 *
69 * @brief The position that data is written to or read from.
70 * @param iohandler The <tt>cmsIOHANDLER</tt> on which to operate
71 * @returns The position that data is written to or read from. */
72cmsUInt32Number IOHandlerFactory::tell(cmsIOHANDLER *iohandler)
73{
74 const QFile *const myFile = static_cast<QFile *>(iohandler->stream);
75 return static_cast<cmsUInt32Number>(myFile->pos());
76}
77
78/** @internal
79 *
80 * @brief Writes data to stream.
81 *
82 * Also keeps used space for further reference.
83 *
84 * @param iohandler The <tt>cmsIOHANDLER</tt> on which to operate
85 * @param size The size of the buffer that should be written
86 * @param Buffer The buffer that should be written
87 * @returns Returns <tt>true</tt> on success, <tt>false</tt> on error.
88 *
89 * @note Because @ref IOHandlerFactory only provides support for read-only
90 * handlers, this function does nothing and returns always <tt>false</tt>. */
91cmsBool IOHandlerFactory::write(cmsIOHANDLER *iohandler, cmsUInt32Number size, const void *Buffer)
92{
93 Q_UNUSED(iohandler)
94 Q_UNUSED(size)
95 Q_UNUSED(Buffer)
96 return false;
97}
98
99/** @internal
100 *
101 * @brief Closes the file and deletes the file handler.
102 * @param iohandler The <tt>cmsIOHANDLER</tt> on which to operate
103 * @returns <tt>true</tt> on success. */
104cmsBool IOHandlerFactory::close(cmsIOHANDLER *iohandler)
105{
106 QFile *const myFile = static_cast<QFile *>(iohandler->stream);
107 delete myFile; // This will also close the file.
108 iohandler->stream = nullptr;
109 _cmsFree(iohandler->ContextID, iohandler);
110 return true;
111}
112
113/** @brief Create a read-only LittleCMS IO handler for a file.
114 *
115 * The handler has to be deleted with <tt>cmsCloseIOhandler</tt>
116 * to free memory once it is not used anymore.
117 *
118 * @param ContextID Handle to user-defined context, or <tt>nullptr</tt> for
119 * the global context
120 * @param fileName Name of the file. See QFile::setFileName() for
121 * the valid format. This format is portable, has standardized directory
122 * separators and supports Unicode file names on all platforms.
123 * @returns On success, a pointer to a new IO handler. On fail,
124 * <tt>nullptr</tt>. The function might fail when the file does not
125 * exist or cannot be opened for reading.
126 *
127 * @internal
128 *
129 * @note The type of the return value is not fully defined
130 * in <tt>lcms2.h</tt> but only in <tt>lcms2_plugin.h</tt>. This is
131 * the expected behaviour for an opaque handle. */
132cmsIOHANDLER *IOHandlerFactory::createReadOnly(cmsContext ContextID, const QString &fileName)
133{
134 cmsIOHANDLER *const result = static_cast<cmsIOHANDLER *>( //
135 _cmsMallocZero(ContextID, sizeof(cmsIOHANDLER)) //
136 );
137 if (result == nullptr) {
138 return nullptr;
139 }
140
141 QFile *const fileObject = new QFile(fileName);
142 if (fileObject == nullptr) {
143 return nullptr;
144 }
145
146 const bool openSucceeded = fileObject->open(QIODevice::ReadOnly);
147 const qint64 fileSize = fileObject->size();
148 // Check if the size is not negative (this might be an error indicator)
149 // neither too big for LittleCMS’s data types:
150 const bool isFileSizeOkay = PerceptualColor::isInRange<qint64>( //
151 0,
152 fileSize,
153 std::numeric_limits<cmsInt32Number>::max());
154 if ((!openSucceeded) || (!isFileSizeOkay)) {
155 delete fileObject;
156 _cmsFree(ContextID, result);
157 return nullptr;
158 }
159
160 // Initialize data members
161 result->ContextID = ContextID;
162 // static_cast loses integer precision: 'qint64' to 'cmsInt32Number'.
163 // This is okay because we have tested yet that the file is not that big.
164 result->ReportedSize = static_cast<cmsUInt32Number>(fileSize);
165 result->stream = static_cast<void *>(fileObject);
166 result->UsedSpace = 0;
167 result->PhysicalFile[0] = 0;
168
169 // Initialize function pointers
170 result->Read = read;
171 result->Seek = seek;
172 result->Close = close;
173 result->Tell = tell;
174 result->Write = write;
175
176 return result;
177}
178
179} // namespace PerceptualColor
The namespace of this library.
bool open(FILE *fh, OpenMode mode, FileHandleFlags handleFlags)
virtual qint64 size() const const override
virtual qint64 pos() const const override
virtual bool seek(qint64 pos) override
QByteArray read(qint64 maxSize)
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