Version 5.0 The LEDA User Manual

9.26 Memory Streambuffer ( memory streambuf )
1. Definition
An object mb of the class memory streambuf can be used as source or target stream
for a coder and allows encoding and decoding in memory (i.e. without file accesses).
Every read or write operation is forwarded to a buffer in memory. This buffer is directly
accessible by the user. The length of this buffer is called the capacity of mb. The size
of mb is the number of characters that can be read from or written to the stream before
an underflow/overflow occurs. (In that case the corresponding stream operation returns
EOF (end-of-file).) Thus the capacity is the maximum size that mb can have without
reallocating its buffer.
#include < LEDA/coding/memory streambuf.h >
2. Creation
memory streambuf mb(streamsize buf sz = 0, bool wipe buf = false);
creates an object mb with capacity and size buf sz. The parameter
wipe buf determines whether wipe buffer is called when the buffer
is not needed any more.
memory streambuf mb(char ∗ buf , streamsize buf sz, bool own buf = false,
bool wipe buf = false);
creates an object mb with the memory buffer buf and sets the
capacity and the size to buf sz. If own buf /wipe buf is true, then
buf is deleted/wiped by mb when it is not used anymore. Note that
buf is not copied but it is used as the internal buffer of mb.
3. Operations
void mb.reset( ) moves the internal get and put pointers to the beginning
of the buffer and clears the underflow/overflow
flags.
streamsize mb.get capacity( ) returns the current capacity.
streamsize mb.get size( ) returns the current size.
void mb.set size(streamsize n)
changes the size to n and calls reset. (If n exceeds
the capacity then a new buffer with sufficient capacity
is allocated. The contents of the old buffer are not
copied.)