Buffered Reader read() method

I'm trying to read a data file using the BufferedReader.read() method. Where the file is valid data I cast to a char and build up a string which then gets written to a flat file.
Some of the bytes I need to read are pointers to a position in another file. These I want to read as integers, and I would expect to be able to use the value returned by the read() method directly.
However I have a problem when the pointer byte has a value from hex 80 to 99 (I can see these using 'hex' on a LINUX system). The values returned are not what I would expect eg. where I would expect 128, I get 8364, expecting 130 I get 8218 and 131, I get 402.
Above 159, things appear to be working as I would expect.
Can anyone explain please
Thanks,
Martin

BufferedReader should only be used to read character data. The value you get from the read method is not the value that was in the file. BufferedReader simply reads character data from an underlying Reader. Your underlying reader is probably an InputStreamReader or a FileReader. Both of those readers perform a transformation from the byte data to the characters using some character encoding. If you want the actual values, you must read them from the InputStream directly or use a DataInputStream

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Problem while using read(char[]) method of stream

Hi I am trying to read different xml files, , hence i am using a buffered reader, and the read(char[]) method in the bufferereader.
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Please tell me how i can overcome this.
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org.xml.sax.SAXParseException: Content is not allowed in trailing section.
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Maybe it isn't. I don't know what 'rawContentBuffer' is, but you're assuming that 'ch' is always full when you call rawContentBuffer.append(ch). You need to call rawContentBuffer.append(ch,0,ascii) or some such form if there is one, or make some other arrangement for handling short reads.

Why do I get such low bandwidth using buffered encoder reads?

I have a PXI system with 10 6115 A/D boards and a 6608 timing board. I can do a simultaneous buffered AI at 5 MHz across all 40 channels of the 6115's.
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Why such a huge difference in bandwidth?

I think the difference in bandwidth here is really due to size of the FIFO's present on each device. The 6115 has either a 16 or 32 Mega-Sample FIFO for analog input. If one of the 6115's isn't granted usage of the bus for a "large" amount of time, it can absorb this by backlogging the data into its FIFO until it is granted the bus, at which time the DMA controller will move the data to host memory before the FIFO overflows. The same is not true of the counters on the 6608. Each counter on the 6608 has an effective FIFO size of 2 Samples. This means at high sampling rates, the 6608 cannot withstand "large" amounts of time without being granted usage of the bus. How fast you can go before the counter FIFO overflows is going to be system dependent, but 200 KHz is in line with results I have observed. If you need to go faster, you can use two counter measurement methods, but you will sacrifice accuracy for speed. For example, by dividing down your input signal by 4, you will be able to go 4 times as fast, but your accuracy will also decrease by a factor of 4. You'll have to weigh the requirements of your application to determine if this type of trade off is acceptable.

How to read the method and put that code in 1 internal table

Hi,
Actually in the normal ABAP, if we want to read the report, then we will write read report statement.
If we want to read method then this statement will not work.
So, to read the method and put that code in 1 internal table , which statement we need to write?
Regards,
Radhika

Hi Naimesh,
Thanks for your reply.
As, i am not aware of ABAP Objects i am having some issues:
Actually that is working for some methods in some classes.
Here 1 issue is there:
In se24 1 method is there in 1 class.
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1 example here:
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in this class, methods like FILE_EXIST , FILE_GET_SIZE, etc are there.
By giving the class name and method name i am able to get the program name also,
but while using that FM in the program i am not able to get that program name.
so, i am unable to read the source code of the program?
Here is my code:
REPORT Z16059_SCAN_METHOD.
DATA: BEGIN OF I_PROGRAM OCCURS 0,
      LINE(256) TYPE C,
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DATA METHOD TYPE PROGRAM.
DATA: BEGIN OF I_STRUCTURE,
      CLS_NAME(30) TYPE C,
      METH_NAME(61) TYPE C,
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I_STRUCTURE-CLS_NAME = 'CL_GUI_FRONTEND_SERVICES'.
I_STRUCTURE-METH_NAME = 'CL_GUI_FRONTEND_SERVICES-FILE_EXIST'.
CALL FUNCTION 'SEO_METHOD_GET_INCLUDE_BY_NAME'
EXPORTING
MTDKEY             = I_STRUCTURE
IMPORTING
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EXCEPTIONS
   INTERNALMETHOD_NOT_EXISTING      = 1
   OTHERS                             = 2
IF SY-SUBRC <> 0.
MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
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ENDIF.
READ REPORT METHOD INTO I_PROGRAM.
Please help me out in this regard.
Thanks & Regards,
Radhika

[SOLVED] Poor SSD Performance, Low Buffered Disk Reads

Hello. Today, I ran hdparm -t and noticed unusually low performance:
/dev/sdb:
Timing buffered disk reads: 342 MB in 3.00 seconds = 113.85 MB/sec
This is on a Samsung 840 EVO with an FX-8320 4.5ghz. Testing /dev/sda, my mechanical hard drive, gives me nearly identical results, which makes pretty much no sense. I ran this about a week ago, and got numbers around 520 MB.
I am using the BFQ scheduler and the Linux-ck kernel. I tried other IO schedulers, but only gotten worsened performance.
The only thing I can think of that I've changed recently was from the performance to ondemand CPU governor. Could that have caused this?
Any help would be appreciated. I am using UEFI/GPT. uname -a:
Linux msw1 3.13.11-2-ck #1 SMP PREEMPT Fri Apr 25 20:19:47 PDT 2014 x86_64 GNU/Linux
EDIT:
Now solved! It turns out the 840 EVO with its TLC NAND is an odd SSD, and that the alignment needs to be a multiple of 1.5.
Last edited by msw1 (2014-05-01 21:28:31)

supermariolinux wrote:
I have the same SSD(840 EVO) as you do and i am getting similar results with hdparm -t, although i thought this had something to do with the fact that my SSD is only connected to SATA 2.
Partitions are aligned and manually trimming the partition doesn't seem to change anything.
I noticed there is new firmware update available on Samsung's website(You can boot from a CD with the ISO without having to use Windows), unfortunately i cannot get it to work as the program just crashes.
Using the standard 3.14.1-1 x86-64 kernel with default cfq scheduler
EDIT: It appears i already have the latest firmware installed, still i recommend checking with
hdparm -i /dev/sdX | grep FwRev
and seeing if new firmware is availbe here: http://www.samsung.com/global/business/ … oads.html#
hparm -t results:
/dev/sdc:
Timing buffered disk reads: 368 MB in 3.01 seconds = 122.36 MB/sec
I do have the latest firmware. As for you, it could be SATA2. I, however, have this connected to a SATA3 controller. As I said, this used to get 500+ easily. Now, it's more like 80.
gedgon wrote:I had exactly the same issue with my EVO when it was not aligned to EBS. It's 1536 KiB or 2048 KiB (depending of source), so it's safe to set the sector alignment value to 12288 (6144 KiB), multiple of 1536 KiB and 2048 KiB.
I wish this solved it. However, I still get the same result:
sudo blockdev --getalignoff /dev/sdb
0

Need official interpretation - java.io.Reader read(char[] cbuf) method

Hello Everyone,
I need Sun API's official interpretation on java.io.Reader read(char[] cbuf) method;
Say, I provide this read method a char[] of size 8096, could the implementing class return even before reading into the whole buffer array? Say, the implementing class just reads 1024 chars and return 1024 as the method output, has the implementing class fulfilled its obligation?
In my mind, the read method should attempt to read and fill the buffer array until of course i/o error occurs or end of stream is reached? See BufferedReader source for this type of implementation.
Or could the read method just attempt to read into the buffer (with no obligation) and can return before completely filling the buffer?
Sincere Regards.

This is the situation: (and we are caught in between arbitrating on whom to ask to make the fix)
Please note that I am not taking any names here, but remember these vendors are the biggest in their market.
Vendor Db A has an API wherein it returns a stream and its length;
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Initially, I thought, Vendor B must fix the code to handle partial reads. But no where it is mentioned clearly that Reader.read only attempts to read the chars and can return before filling the buffer.
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BIJ001, No problem in your explanation. I understand and I am merely pointing you to alternate interpretation of the API.
Please comment. Thanks for your time to discuss this.
Sincere Regards.

Question for Reader.read() !

When I read the documentation for Reader.read(), I am not sure if I understand it right or not.
public int read():
Read a single character. This method will block until a character is available, an I/O error occurs, or the end of the stream is reached.
Depends on what it saying, I think when read() is called, it will always move its cursor to the next, read next character, if it is possible.
Am I right? Any code to prove that? I am trying to do it in my own, if I get it, I will post to here too.

Yeah you're right.
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Hi,
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