ECode FileUtils::ChecksumCrc32(
/* [in] */ IFile* file,
/* [out] */ Int64* summer)
{
VALIDATE_NOT_NULL(file);
VALIDATE_NOT_NULL(summer);
*summer = 0;
AutoPtr<ArrayOf<Byte> > buf;
Int32 length;
AutoPtr<ICRC32> checkSummer;
CCRC32::New((ICRC32**)&checkSummer);
AutoPtr<IFileInputStream> input;
CFileInputStream::New(file, (IFileInputStream**)&input);
IInputStream* is;
AutoPtr<ICheckedInputStream> cis;
ECode ec = CCheckedInputStream::New(
IInputStream::Probe(input),
IChecksum::Probe(checkSummer), (ICheckedInputStream**)&cis);
FAIL_GOTO(ec, _EXIT_);
is = IInputStream::Probe(cis);
buf = ArrayOf<Byte>::Alloc(128);
while(is->Read(buf, &length), length >= 0) {
// Just read for checksum to get calculated.
}
IChecksum::Probe(checkSummer)->GetValue(summer);
_EXIT_:
if (cis != NULL) {
ICloseable::Probe(cis)->Close();
}
return ec;
}
ECode FileUtils::ReadTextFile(
/* [in] */ IFile* file,
/* [in] */ Int32 max,
/* [in] */ const String& ellipsis,
/* [out] */ String* result)
{
VALIDATE_NOT_NULL(result);
*result = String("");
VALIDATE_NOT_NULL(file);
AutoPtr<IInputStream> input;
AutoPtr<IBufferedInputStream> bis;
Int64 size;
Int32 length;
AutoPtr<ArrayOf<Byte> > data, last, tmp;
Boolean rolled = FALSE;
AutoPtr<IByteArrayOutputStream> contents;
IInputStream* is;
IOutputStream* os;
ECode ec = CFileInputStream::New(file, (IInputStream**)&input);
FAIL_GOTO(ec, _EXIT_);
// wrapping a BufferedInputStream around it because when reading /proc with unbuffered
// input stream, bytes read not equal to buffer size is not necessarily the correct
// indication for EOF; but it is true for BufferedInputStream due to its implementation.
ec = CBufferedInputStream::New(input, (IBufferedInputStream**)&bis);
FAIL_GOTO(ec, _EXIT_);
is = IInputStream::Probe(bis);
file->GetLength(&size);
if (max > 0 || (size > 0 && max == 0)) { // "head" mode: read the first N bytes
if (size > 0 && (max == 0 || size < max)) max = (Int32) size;
data = ArrayOf<Byte>::Alloc(max + 1);
is->Read(data, &length);
if (length <= 0) {
*result = String("");
}
else if (length <= max) {
*result = String((const char *)(data->GetPayload()), length);
}
else if (ellipsis.IsNull()) {
*result = String((const char *)(data->GetPayload()), max);
}
else {
*result = String((const char *)(data->GetPayload()), max);
*result += ellipsis;
}
}
else if (max < 0) { // "tail" mode: keep the last N
do {
if (last != NULL) rolled = true;
tmp = last; last = data; data = tmp;
if (data == NULL) data = ArrayOf<Byte>::Alloc(-max);
is->Read(data, &length);
} while (length == data->GetLength());
if (last == NULL && length <= 0) {
*result = String("");
goto _EXIT_;
}
if (last == NULL) {
*result = String((const char *)(data->GetPayload()), length);
goto _EXIT_;
}
if (length > 0) {
rolled = true;
last->Copy(length, last, 0, last->GetLength() - length);
last->Copy(last->GetLength() - length, data, 0, length);
// System.arraycopy(last, length, last, 0, last.length - length);
// System.arraycopy(data, 0, last, last.length - len, length);
}
if (ellipsis == NULL || !rolled) {
*result = String((const char *)(last->GetPayload()), last->GetLength());
}
else {
*result = ellipsis;
*result += String((const char *)(last->GetPayload()), last->GetLength());
}
}
else { // "cat" mode: size unknown, read it all in streaming fashion
CByteArrayOutputStream::New((IByteArrayOutputStream**)&contents);
os = IOutputStream::Probe(contents);
data = ArrayOf<Byte>::Alloc(1024);
do {
is->Read(data, &length);
if (length > 0) os->Write(data, 0, length);
} while (length == data->GetLength());
contents->ToString(result);
}
_EXIT_:
if (bis) ICloseable::Probe(bis)->Close();
if (input) ICloseable::Probe(input)->Close();
return ec;
}
