connectivity/source/drivers/jdbc/Reader.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <java/io/Reader.hxx>
  21 #include <string.h>
  22 #include <osl/diagnose.h>
  23 using namespace connectivity;
  24 using ::com::sun::star::uno::Sequence;
  25
  26
  27 //************ Class: java.io.Reader
  28
  29
  30 jclass java_io_Reader::theClass = nullptr;
  31 java_io_Reader::java_io_Reader( JNIEnv * pEnv, jobject myObj )
  32     : java_lang_Object( pEnv, myObj )
  33 {
  34     SDBThreadAttach::addRef();
  35 }
  36 java_io_Reader::~java_io_Reader()
  37 {
  38     SDBThreadAttach::releaseRef();
  39 }
  40
  41 jclass java_io_Reader::getMyClass() const
  42 {
  43     // the class must be fetched only once, therefore static
  44     if( !theClass )
  45         theClass = findMyClass("java/io/Reader");
  46     return theClass;
  47 }
  48
  49 sal_Int32 SAL_CALL java_io_Reader::readSomeBytes( css::uno::Sequence< sal_Int8 >& aData, sal_Int32 nMaxBytesToRead )
  50 {
  51     return readBytes(aData,nMaxBytesToRead);
  52 }
  53
  54 void SAL_CALL java_io_Reader::skipBytes( sal_Int32 nBytesToSkip )
  55 {
  56     static jmethodID mID(nullptr);
  57     if(nBytesToSkip <= 0)
  58         return;
  59
  60     if(m_buf)
  61     {
  62         m_buf.reset();
  63         --nBytesToSkip;
  64     }
  65
  66     static_assert(sizeof(jchar) == 2, "I thought Java characters were UTF16 code units?");
  67     sal_Int32 nCharsToSkip = nBytesToSkip / sizeof(jchar);
  68     callIntMethodWithIntArg_ThrowRuntime("skip",mID,nCharsToSkip);
  69     if(nBytesToSkip % sizeof(jchar) != 0)
  70     {
  71         assert(nBytesToSkip % sizeof(jchar) == 1);
  72         Sequence< sal_Int8 > aData(1);
  73         assert(m_buf);
  74         readBytes(aData, 1);
  75     }
  76 }
  77
  78 sal_Int32 SAL_CALL java_io_Reader::available(  )
  79 {
  80     if(m_buf)
  81         return 1;
  82     bool out;
  83     SDBThreadAttach t; OSL_ENSURE(t.pEnv,"Java environment has been deleted!");
  84
  85     {
  86         static const char * const cSignature = "()Z";
  87         static const char * const cMethodName = "ready";
  88         // Java-Call
  89         static jmethodID mID(nullptr);
  90         obtainMethodId_throwRuntime(t.pEnv, cMethodName,cSignature, mID);
  91         out = t.pEnv->CallBooleanMethod( object, mID);
  92         ThrowRuntimeException(t.pEnv,*this);
  93     } //t.pEnv
  94     return (m_buf ? 1 : 0) + (out ? 1 : 0); // no way to tell *how much* is ready
  95 }
  96
  97 void SAL_CALL java_io_Reader::closeInput(  )
  98 {
  99     static jmethodID mID(nullptr);
 100     callVoidMethod_ThrowRuntime("close", mID);
 101 }
 102
 103 sal_Int32 SAL_CALL java_io_Reader::readBytes( css::uno::Sequence< sal_Int8 >& aData, sal_Int32 nBytesToRead )
 104 {
 105     OSL_ENSURE(aData.getLength() >= nBytesToRead," Sequence is smaller than BytesToRead");
 106
 107     if(nBytesToRead == 0)
 108         return 0;
 109
 110     sal_Int8 *dst(aData.getArray());
 111     sal_Int32 nBytesWritten(0);
 112
 113     if (m_buf)
 114     {
 115         if(!aData.hasElements())
 116         {
 117             aData.realloc(1);
 118             dst = aData.getArray();
 119         }
 120         *dst = *m_buf;
 121         m_buf.reset();
 122         ++nBytesWritten;
 123         ++dst;
 124         --nBytesToRead;
 125     }
 126
 127     if(nBytesToRead == 0)
 128         return nBytesWritten;
 129
 130     sal_Int32 nCharsToRead = (nBytesToRead + 1)/2;
 131
 132     SDBThreadAttach t; OSL_ENSURE(t.pEnv,"Java environment has been deleted!");
 133
 134     {
 135         jcharArray pCharArray = t.pEnv->NewCharArray(nCharsToRead);
 136         static const char * const cSignature = "([CII)I";
 137         static const char * const cMethodName = "read";
 138         // Java-Call
 139         static jmethodID mID(nullptr);
 140         obtainMethodId_throwRuntime(t.pEnv, cMethodName,cSignature, mID);
 141         jint outChars = t.pEnv->CallIntMethod( object, mID, pCharArray, 0, nCharsToRead );
 142         if ( !outChars )
 143         {
 144             if(nBytesWritten==0)
 145                 ThrowRuntimeException(t.pEnv,*this);
 146             else
 147                 return 1;
 148         }
 149         if(outChars > 0)
 150         {
 151             static_assert(sizeof(jchar) == 2, "I thought Java characters were UTF16 code units?");
 152             const sal_Int32 jcs = sizeof(jchar);
 153             const sal_Int32 outBytes = std::min(nBytesToRead, outChars*jcs);
 154             assert(outBytes == outChars*jcs || outBytes == outChars*jcs - 1);
 155
 156             jboolean p = JNI_FALSE;
 157             if(aData.getLength() < nBytesWritten + outBytes)
 158             {
 159                 aData.realloc(nBytesWritten + outBytes);
 160                 dst = aData.getArray() + nBytesWritten;
 161             }
 162             jchar *outBuf(t.pEnv->GetCharArrayElements(pCharArray,&p));
 163
 164             memcpy(dst, outBuf, outBytes);
 165             nBytesWritten += outBytes;
 166             if(outBytes < outChars*jcs)
 167             {
 168                 assert(outChars*jcs - outBytes == 1);
 169                 assert(!m_buf);
 170                 m_buf = reinterpret_cast<char*>(outBuf)[outBytes];
 171             }
 172         }
 173         t.pEnv->DeleteLocalRef(pCharArray);
 174     } //t.pEnv
 175     return nBytesWritten;
 176 }
 177
 178 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */