EDOBE XDOM PMML Uživatelský manuál stáhnout pdf (Strana 74)

single buf reader can access the data sequentially, or read the data in

multiple passes or via random access. As different parts of the data

are accessed, they are read into memory from the backing file.

CNKBackingFileBuf backing file (also called a "data cache file")

contains a packed binary representation of the data values. In order

for a

CNKBackingFileBuf to read an existing data cache file, it must

be set with the same column specification as was used to create it, so it

knows the number of columns, factor levels, etc.

CNKBackingFileBuf::

CNKBackingFileBuf();

virtual ~CNKBackingFileBuf();

virtual void init();

These are the CNKBackingFileBuf constructor, destructor and init()

methods. A

CNKBackingFileBuf object is created with

CNKBackingFileBuf(), then the properties of the columns and the

readers and writers are created, and then

init() is called to initialize

it, which allocates the storage for the buffer data, and opens the

backing file.

CNKBackingFileBuf::

void setBackingFileName(const char* nam);

const char* getBackingFileName();

Access the name of the backing file. If this is set to NULL, an error is

set on

init().

CNKBackingFileBuf::

void setBackingFileTotalRows(INT64 val);

INT64 getBackingFileTotalRows();

Set/get the initial number of rows in the backing file. When using a

CNKBackingFileBuf to write a backing file, this should be set to 0.

When using a

CNKBackingFileBuf to read a backing file, this should

be set to the number of rows of data in the file.

CNKBackingFileBuf::

long getBackingFileRowBytes();

long getBackingFileColumnOffsetBytes(int colNum);

int getBackingFileColumnWidthBytes(int colNum);

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EDOBE XDOM PMML Uživatelský manuál Strana 74