rheostream(2rheolef) rheolef-6.1 rheostream(2rheolef)
NAME
irheostream, orheostream - large data streams
ABSTRACT
This class provides a stream interface for large
data management.
File decompresion is assumed using
gzip and a recursive seach in a directory list
is provided for input.
orheostream foo("NAME", "suffix");
is like
ofstream foo("NAME.suffix").
However, if NAME does not end with `.suffix', then
`.suffix' is added, and compression
is done with gzip, adding an additional `.gz' suffix.
Conversely,
irheostream foo("NAME","suffix");
is like
ifstream foo("NAME.suffix").
However, we look at a search path environment variable
RHEOPATH in order to find NAME while suffix is assumed.
Moreover, gzip compressed files, ending
with the `.gz' suffix is assumed, and decompression is done.
Finally, a set of useful functions are provided.
DESCRIPTION
The following code:
irheostream is("results", "data");
will recursively look for a `results[.data[.gz]]' file in the
directory mentionned by the RHEOPATH environment variable.
For instance, if you insert in our ".cshrc" something like:
setenv RHEOPATH ".:/home/dupont:/usr/local/math/demo"
the process will study the current directory `.', then, if
neither `square.data.gz' nor `square.data' exits, it scan
all subdirectory of the current directory. Then, if file
is not founded, it start recusively in `/home/dupond'
and then in `/usr/local/math/demo'.
File decompression is performed by using
the gzip command, and data are pipe-lined
directly in memory.
If the file start with `.' as `./square' or with a `/'
as `/home/oscar/square', no search occurs and RHEOPATH
environment variable is not used.
Also, if the environment variable RHEOPATH is not set, the
default value is the current directory `.'.
For output stream:
orheostream os("newresults", "data");
file compression is assumed, and "newresults.data.gz"
will be created.
File loading and storing are mentionned by a message,
either:
! load "./results.data.gz"
or:
! file "./newresults.data.gz" created.
on the clog stream.
By adding the following:
clog << noverbose;
you turn off these messages
(see iorheo(4)).
IMPLEMENTATION
class irheostream : public io::filtering_stream<io::input> {
public:
irheostream() : io::filtering_stream<io::input>() {}
irheostream(const std::string& name, const std::string& suffix = std::string());
virtual ~irheostream();
void open (const std::string& name, const std::string& suffix = std::string());
void close();
protected:
std::ifstream _ifs;
};
class orheostream : public io::filtering_stream<io::output> {
public:
orheostream() : io::filtering_stream<io::output>() {}
orheostream(const std::string& name, const std::string& suffix = std::string());
virtual ~orheostream();
void open (const std::string& name, const std::string& suffix = std::string());
void close();
protected:
std::ofstream _ofs;
};
std::string itos (std::string::size_type i);
std::string ftos (const Float& x);
// catch first occurence of string in file
bool scatch (std::istream& in, const std::string& ch);
// has_suffix("toto.suffix", "suffix") -> true
bool has_suffix (const std::string& name, const std::string& suffix);
// "toto.suffix" --> "toto"
std::string delete_suffix (const std::string& name, const std::string& suffix);
// "/usr/local/dir/toto.suffix" --> "toto.suffix"
std::string get_basename (const std::string& name);
// "/usr/local/dir/toto.suffix" --> "/usr/local/dir"
std::string get_dirname (const std::string& name);
// "toto" --> "/usr/local/math/data/toto.suffix"
std::string get_full_name_from_rheo_path (const std::string& rootname, const std::string& suffix);
// "." + "../geodir" --> ".:../geodir"
void append_dir_to_rheo_path (const std::string& dir);
// "../geodir" + "." --> "../geodir:."
void prepend_dir_to_rheo_path (const std::string& dir);
bool file_exists (const std::string& filename);
// string to float
bool is_float (const std::string&);
Float to_float (const std::string&);
// in TMPDIR environment variable or "/tmp" by default
std::string get_tmpdir();
SEE ALSO
iorheo(4)
rheolef-6.1 rheolef-6.1 rheostream(2rheolef)