QCryptographicHash: allow to hash the content of a QIODevice

This adds a new function (and tests) to give the possibility of doing a
QCryptographicHash of a QIODevice, like a QFile or whatever people
needs.

It is a quite handy overload in many cases.

Change-Id: I22fd272f05571844641b3daefcc6746be4e5c7c3
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

2 files changed, 25 insertions, 0 deletions

diff --git a/src/corelib/tools/qcryptographichash.cpp b/src/corelib/tools/qcryptographichash.cpp
index 89b3bab7c6..e5ac73c3f5 100644
--- a/src/corelib/tools/qcryptographichash.cpp
+++ b/src/corelib/tools/qcryptographichash.cpp
@@ -50,6 +50,7 @@
 #include "../../3rdparty/md4/md4.h"
 #include "../../3rdparty/md4/md4.cpp"
 #include "../../3rdparty/sha1/sha1.cpp"
+#include <qiodevice.h>
 
 
 QT_BEGIN_NAMESPACE
@@ -155,6 +156,28 @@ void QCryptographicHash::addData(const QByteArray &data)
 }
 
 /*!
+  Reads the data from the open QIODevice \a device until it ends
+  and hashes it. Returns true if reading was successful.
+ */
+bool QCryptographicHash::addData(QIODevice* device)
+{
+    if (!device->isReadable())
+        return false;
+
+    if (!device->isOpen())
+        return false;
+
+    char buffer[1024];
+    int length;
+
+    while ((length = device->read(buffer,sizeof(buffer))) > 0)
+        addData(buffer,length);
+
+    return device->atEnd();
+}
+
+
+/*!
   Returns the final hash value.
 
   \sa QByteArray::toHex()
diff --git a/src/corelib/tools/qcryptographichash.h b/src/corelib/tools/qcryptographichash.h
index b40e8cc25b..15ebd22418 100644
--- a/src/corelib/tools/qcryptographichash.h
+++ b/src/corelib/tools/qcryptographichash.h
@@ -51,6 +51,7 @@ QT_BEGIN_NAMESPACE
 QT_MODULE(Core)
 
 class QCryptographicHashPrivate;
+class QIODevice;
 
 class Q_CORE_EXPORT QCryptographicHash
 {
@@ -68,6 +69,7 @@ public:
 
     void addData(const char *data, int length);
     void addData(const QByteArray &data);
+    bool addData(QIODevice* device);
 
     QByteArray result() const;