qresource.cpp

QT 开发环境里面一个很重要的文件

}

/*!
    Returns direct access to a read only segment of data that this resource
    represents. If the resource is compressed the data returns is
    compressed and qUncompress() must be used to access the data. If the
    resource is a directory 0 is returned.

    \sa size(), isCompressed(), isFile()
*/

const uchar *QResource::data() const
{
    Q_D(const QResource);
    d->ensureInitialized();
    return d->data;
}

/*!
    Returns true if the resource represents a directory and thus may have
    children() in it, false if it represents a file.

    \sa isFile()
*/

bool QResource::isDir() const
{
    Q_D(const QResource);
    d->ensureInitialized();
    return d->container;
}

/*!
    Returns a list of all resources in this directory, if the resource
    represents a file the list will be empty.

    \sa isDir()
*/

QStringList QResource::children() const
{
    Q_D(const QResource);
    d->ensureChildren();
    return d->children;
}

/*!
  Adds \a path to the search paths searched in to find resources that are
  not specified with an absolute path. The \a path must be an absolute
  path (start with \c{/}).

  The default search path is to search only in the root (\c{:/}). The last
  path added will be consulted first upon next QResource creation.
*/

void
QResource::addSearchPath(const QString &path)
{
    if (!path.startsWith(QLatin1Char('/'))) {
        qWarning("QDir::addResourceSearchPath: Search paths must be absolute (start with /) [%s]",
                 path.toLocal8Bit().data());
        return;
    }
    QMutexLocker lock(resourceMutex());
    resourceSearchPaths()->prepend(path);
}

/*!
  Returns the current search path list. This list is consulted when
  creating a relative resource.

  \sa addSearchPath()
*/

QStringList
QResource::searchPaths()
{
    QMutexLocker lock(resourceMutex());
    return *resourceSearchPaths();
}

inline int QResourceRoot::hash(int node) const
{
    if(!node) //root
        return 0;
    const int offset = findOffset(node);
    int name_offset = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                      (tree[offset+2] << 8) + (tree[offset+3] << 0);
    name_offset += 2; //jump past name length
    return (names[name_offset+0] << 24) + (names[name_offset+1] << 16) +
           (names[name_offset+2] << 8) + (names[name_offset+3] << 0);
}
inline QString QResourceRoot::name(int node) const
{
    if(!node) // root
        return QString();
    const int offset = findOffset(node);

    QString ret;
    int name_offset = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                      (tree[offset+2] << 8) + (tree[offset+3] << 0);
    const short name_length = (names[name_offset+0] << 8) +
                              (names[name_offset+1] << 0);
    name_offset += 2;
    name_offset += 4; //jump past hash
    for(int i = 0; i < name_length*2; i+=2)
        ret += QChar(names[name_offset+i+1], names[name_offset+i]);
    return ret;
}
int QResourceRoot::findNode(const QString &_path, const QLocale &locale) const
{
    QString path = _path;
    {
        QString root = mappingRoot();
        if(!root.isEmpty()) {
            if(root == path) {
                path = QLatin1String("/");
            } else {
                if(!root.endsWith(QLatin1String("/")))
                    root += QLatin1String("/");
                if(path.size() >= root.size() && path.startsWith(root))
                    path = path.mid(root.length()-1);
                if(path.isEmpty())
                    path = QLatin1String("/");
            }
        }
    }
    if(path == QLatin1String("/"))
        return 0;

    //the root node is always first
    int child_count = (tree[6] << 24) + (tree[7] << 16) +
                      (tree[8] << 8) + (tree[9] << 0);
    int child       = (tree[10] << 24) + (tree[11] << 16) +
                      (tree[12] << 8) + (tree[13] << 0);

    //now iterate up the tree
    int node = -1;
    QStringList segments = path.split(QLatin1Char('/'), QString::SkipEmptyParts);
    for(int i = 0; child_count && i < segments.size(); ++i) {
        const QString &segment = segments[i];
        const int h = qHash(segment);

        //do the binary search for the hash
        int l = 0, r = child_count-1;
        int sub_node = (l+r+1)/2;
        while(r != l) {
            const int sub_node_hash = hash(child+sub_node);
            if(h == sub_node_hash)
                break;
            else if(h < sub_node_hash)
                r = sub_node - 1;
            else
                l = sub_node;
            sub_node = (l + r + 1) / 2;
        }
        sub_node += child;

        //now do the "harder" compares
        bool found = false;
        if(hash(sub_node) == h) {
            while(sub_node > child && hash(sub_node-1) == h) //backup for collisions
                --sub_node;
            for(; sub_node < child+child_count && hash(sub_node) == h; ++sub_node) { //here we go...
                if(name(sub_node) == segment) {
                    found = true;
                    int offset = findOffset(sub_node) + 4; //jump past name

                    const short flags = (tree[offset+0] << 8) +
                                        (tree[offset+1] << 0);
                    offset += 2;

                    if(i == segments.size()-1) {
                        if(!(flags & Directory)) {
                            const short country = (tree[offset+0] << 8) +
                                                  (tree[offset+1] << 0);
                            offset += 2;

                            const short language = (tree[offset+0] << 8) +
                                                   (tree[offset+1] << 0);
                            offset += 2;

                            if(country == locale.country() && language == locale.language())
                                return sub_node;
                            else if((country == QLocale::AnyCountry && language == locale.language()) ||
                                    (country == QLocale::AnyCountry && language == QLocale::C && node == -1))
                                node = sub_node;
                            continue;
                        } else {
                            return sub_node;
                        }
                    }

                    if(!(flags & Directory))
                        return -1;

                    child_count = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                                  (tree[offset+2] << 8) + (tree[offset+3] << 0);
                    offset += 4;
                    child = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                            (tree[offset+2] << 8) + (tree[offset+3] << 0);
                    break;
                }
            }
        }
        if(!found)
            break;
    }
    return node;
}
short QResourceRoot::flags(int node) const
{
    if(node == -1)
        return 0;
    const int offset = findOffset(node) + 4; //jump past name
    return (tree[offset+0] << 8) + (tree[offset+1] << 0);
}
const uchar *QResourceRoot::data(int node, qint64 *size) const
{
    if(node == -1) {
        *size = 0;
        return 0;
    }
    int offset = findOffset(node) + 4; //jump past name

    const short flags = (tree[offset+0] << 8) + (tree[offset+1] << 0);
    offset += 2;

    offset += 4; //jump past locale

    if(!(flags & Directory)) {
        const int data_offset = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                                (tree[offset+2] << 8) + (tree[offset+3] << 0);
        const uint data_length = (payloads[data_offset+0] << 24) + (payloads[data_offset+1] << 16) +
                                 (payloads[data_offset+2] << 8) + (payloads[data_offset+3] << 0);
        const uchar *ret = payloads+data_offset+4;
        *size = data_length;
        return ret;
    }
    *size = 0;
    return 0;
}
QStringList QResourceRoot::children(int node) const
{
    if(node == -1)
        return QStringList();
    int offset = findOffset(node) + 4; //jump past name

    const short flags = (tree[offset+0] << 8) + (tree[offset+1] << 0);
    offset += 2;

    QStringList ret;
    if(flags & Directory) {
        const int child_count = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                                (tree[offset+2] << 8) + (tree[offset+3] << 0);
        offset += 4;
        const int child_off = (tree[offset+0] << 24) + (tree[offset+1] << 16) +
                              (tree[offset+2] << 8) + (tree[offset+3] << 0);
        for(int i = child_off; i < child_off+child_count; ++i)
            ret << name(i);
    }
    return ret;
}
bool QResourceRoot::mappingRootSubdir(const QString &path, QString *match) const
{
    const QString root = mappingRoot();
    if(!root.isEmpty()) {
        const QStringList root_segments = root.split(QLatin1Char('/'), QString::SkipEmptyParts),
                          path_segments = path.split(QLatin1Char('/'), QString::SkipEmptyParts);
        if(path_segments.size() <= root_segments.size()) {
            int matched = 0;
            for(int i = 0; i < path_segments.size(); ++i) {
                if(root_segments[i] != path_segments[i])
                    break;
                ++matched;
            }
            if(matched == path_segments.size()) {
                if(match && root_segments.size() > matched)
                    *match = root_segments.at(matched);
                return true;
            }
        }
    }
    return false;
}

Q_CORE_EXPORT bool qRegisterResourceData(int version, const unsigned char *tree,
                                         const unsigned char *name, const unsigned char *data)
{
    QMutexLocker lock(resourceMutex());
    if(version == 0x01 && resourceList()) {
        bool found = false;
        QResourceRoot res(tree, name, data);
        for(int i = 0; i < resourceList()->size(); ++i) {
            if(*resourceList()->at(i) == res) {
                found = true;
                break;
            }
        }
        if(!found) {
            QResourceRoot *root = new QResourceRoot(tree, name, data);
            root->ref.ref();
            resourceList()->append(root);
        }
        return true;
    }
    return false;
}

Q_CORE_EXPORT bool qUnregisterResourceData(int version, const unsigned char *tree,
                                           const unsigned char *name, const unsigned char *data)
{
    QMutexLocker lock(resourceMutex());
    if(version == 0x01 && resourceList()) {
        QResourceRoot res(tree, name, data);
        for(int i = 0; i < resourceList()->size(); ) {
            if(*resourceList()->at(i) == res) {
                QResourceRoot *root = resourceList()->takeAt(i);
                if(!root->ref.deref())
                    delete root;
            } else {
                ++i;
            }
        }
        return true;
    }
    return false;
}

//run time resource creation

#if defined(Q_OS_UNIX)
#define QT_USE_MMAP
#endif

// most of the headers below are already included in qplatformdefs.h
// also this lacks Large File support but that's probably irrelevant
#if defined(QT_USE_MMAP)
// for mmap
#include <sys/mman.h>
#include <errno.h>
#endif

class QDynamicResourceRoot: public QResourceRoot
{
    QString root, fileName;
    // for mmap'ed files, this is what needs to be unmapped.
    uchar *unmapPointer;
    unsigned int unmapLength;
    bool fromMM;

public:
    inline QDynamicResourceRoot(const QString &_root) : root(_root), unmapPointer(0), unmapLength(0) { }
    ~QDynamicResourceRoot() {
        if (unmapPointer && unmapLength) {
#if defined(QT_USE_MMAP)
            if(fromMM)
                munmap((char*)unmapPointer, unmapLength);
            else
#endif
                delete [] unmapPointer;
            unmapPointer = 0;
            unmapLength = 0;
        }
    }
    QString mappingFile() const { return fileName; }
    virtual QString mappingRoot() const { return root; }
    virtual bool isDynamicRoot() const { return true; }

    bool registerSelf(const QString &f) {
        bool ok = false;
#ifdef QT_USE_MMAP

#ifndef MAP_FILE
#define MAP_FILE 0
#endif
#ifndef MAP_FAILED
#define MAP_FAILED -1
#endif

        int fd = QT_OPEN(QFile::encodeName(f), O_RDONLY,
#if defined(Q_OS_WIN)
                         _S_IREAD | _S_IWRITE
#else
                         0666
#endif
            );
        if (fd >= 0) {
            struct stat st;
            if (!fstat(fd, &st)) {
                uchar *ptr;
                ptr = reinterpret_cast<uchar *>(
                    mmap(0, st.st_size,             // any address, whole file
                         PROT_READ,                 // read-only memory
                         MAP_FILE | MAP_PRIVATE,    // swap-backed map from file
                         fd, 0));                   // from offset 0 of fd
                if (ptr && ptr != reinterpret_cast<uchar *>(MAP_FAILED)) {
                    unmapPointer = ptr;
                    unmapLength = st.st_size;
                    fromMM = true;
                    ok = true;
                }
            }
            ::close(fd);
        }
#endif // QT_USE_MMAP
        if(!ok) {
            QFile file(f);
            if (!file.exists())
                return false;
            unmapLength = file.size();
            unmapPointer = new uchar[unmapLength];

            if (file.open(QIODevice::ReadOnly))
                ok = (unmapLength == (uint)file.read((char*)unmapPointer, unmapLength));

            if (!ok) {
                delete [] unmapPointer;
                unmapPointer = 0;
                unmapLength = 0;
                return false;
            }
            fromMM = false;
        }
        if(!ok) {
	    fileName = QString();
            return false;
	}
	fileName = f;