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;
};
static const bool dont_gzip = false;
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(),
        bool use_gzip = true);
    virtual ~orheostream();
    void open  (const std::string& name, const std::string& suffix = std::string(),
        bool use_gzip = true);
    void flush();
    void close();
protected:
    std::ofstream _ofs;
    bool          _use_gzip;
    std::string   _full_name;
};
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, bool full_match = true);

// 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)