I/O Stream 3 RAPTOR Library
I/O Stream Providing streaming I/O writing to files, strings or user code.

## Synopsis

    typedef     raptor_iostream;
    int         (*raptor_iostream_init_func)    (void *context);
    void        (*raptor_iostream_finish_func)  (void *context);
    int         (*raptor_iostream_write_byte_func)
                                                (void *context,
                                                 const int byte);
    int         (*raptor_iostream_write_bytes_func)
                                                (void *context,
                                                 const void *ptr,
                                                 size_t size,
                                                 size_t nmemb);
    void        (*raptor_iostream_write_end_func)
                                                (void *context);
                raptor_iostream_handler;
    raptor_iostream* raptor_new_iostream_from_handler
                                                (void *context,
                                                 const raptor_iostream_handler *handler);
    raptor_iostream* raptor_new_iostream_to_sink
                                                (void);
    raptor_iostream* raptor_new_iostream_to_filename
                                                (const char *filename);
    raptor_iostream* raptor_new_iostream_to_file_handle
                                                (FILE *handle);
    raptor_iostream* raptor_new_iostream_to_string
                                                (void **string_p,
                                                 size_t *length_p,
                                                 void* (*malloc_handler) (size_t size));
    void        raptor_free_iostream            (raptor_iostream *iostr);
    int         raptor_iostream_write_bytes     (raptor_iostream *iostr,
                                                 const void *ptr,
                                                 size_t size,
                                                 size_t nmemb);
    int         raptor_iostream_write_byte      (raptor_iostream *iostr,
                                                 const int byte);
    void        raptor_iostream_write_end       (raptor_iostream *iostr);
    int         raptor_iostream_write_string    (raptor_iostream *iostr,
                                                 const void *string);
    int         raptor_iostream_write_counted_string
                                                (raptor_iostream *iostr,
                                                 const void *string,
                                                 size_t len);
    size_t      raptor_iostream_get_bytes_written_count
                                                (raptor_iostream *iostr);
    int         raptor_iostream_write_decimal   (raptor_iostream *iostr,
                                                 int integer);
    int         raptor_iostream_format_hexadecimal
                                                (raptor_iostream *iostr,
                                                 unsigned int integer,
                                                 int width);
    int         raptor_iostream_write_stringbuffer
                                                (raptor_iostream *iostr,
                                                 raptor_stringbuffer *sb);
    int         raptor_iostream_write_string_ntriples
                                                (raptor_iostream *iostr,
                                                 unsigned char *string,
                                                 size_t len,
                                                 const char delim);
    void        raptor_iostream_write_statement_ntriples
                                                (raptor_iostream *iostr,
                                                 const raptor_statement *statement);

## Description

An class providing an I/O writer abstraction that allows generating output that can be stored or passed on to system files, strings allocated in memory (usually via raptor_stringbuffer), system file handles (`FILE*`) or to a user function.

## Details

### raptor_iostream

    raptor_iostream* raptor_iostream;

Raptor I/O Stream class

raptor_iostream

### raptor_iostream_init_func ()

    int         (*raptor_iostream_init_func)    (void *context);

Handler function for raptor_iostream initialising.

context :

  stream context data

Returns :

  non-0 on failure.

raptor_iostream_init_func

### raptor_iostream_finish_func ()

    void        (*raptor_iostream_finish_func)  (void *context);

Handler function for raptor_iostream terminating.

context :

  stream context data

raptor_iostream_finish_func

### raptor_iostream_write_byte_func ()

    int         (*raptor_iostream_write_byte_func)
                                                (void *context,
                                                 const int byte);

Handler function for implementing `raptor_iostream_write_byte()`.

context :

  stream context data

byte :

  byte to write

Returns :

  non-0 on failure.

raptor_iostream_write_byte_func

### raptor_iostream_write_bytes_func ()

    int         (*raptor_iostream_write_bytes_func)
                                                (void *context,
                                                 const void *ptr,
                                                 size_t size,
                                                 size_t nmemb);

Handler function for implementing `raptor_iostream_write_bytes()`.

context :

  stream context data

ptr :

  pointer to bytes to write

size :

  size of item

nmemb :

  number of items

Returns :

  non-0 on failure.

raptor_iostream_write_bytes_func

### raptor_iostream_write_end_func ()

    void        (*raptor_iostream_write_end_func)
                                                (void *context);

Handler function for implementing `raptor_iostream_write_end()`.

context :

  stream context data

raptor_iostream_write_end_func

### raptor_iostream_handler

    typedef struct {
      raptor_iostream_init_func         init;
      raptor_iostream_finish_func       finish;
      raptor_iostream_write_byte_func   write_byte;
      raptor_iostream_write_bytes_func  write_bytes;
      raptor_iostream_write_end_func    write_end;
    } raptor_iostream_handler;

I/O stream implementation handler structure.

raptor_iostream_init_func init;

  initialisation handler - optional, called at most once

raptor_iostream_finish_func finish;

  finishing handler - optional, called at most once

raptor_iostream_write_byte_func write_byte;

  write byte handler - required

raptor_iostream_write_bytes_func write_bytes;

  write bytes handler - required

raptor_iostream_write_end_func write_end;

  write end handler - optional, called at most once

raptor_iostream_handler

### raptor_new_iostream_from_handler ()

    raptor_iostream* raptor_new_iostream_from_handler
                                                (void *context,
                                                 const raptor_iostream_handler *handler);

Create a new iostream over a user-defined handler.

context :

  pointer to context information to pass in to calls

handler :

  pointer to handler methods

Returns :

  new raptor_iostream object or NULL on failure

raptor_new_iostream_from_handler

### raptor_new_iostream_to_sink ()

    raptor_iostream* raptor_new_iostream_to_sink
                                                (void);

Create a new iostream to a sink.

Returns :

  new raptor_iostream object or NULL on failure

raptor_new_iostream_to_sink

### raptor_new_iostream_to_filename ()

    raptor_iostream* raptor_new_iostream_to_filename
                                                (const char *filename);

Constructor - create a new iostream writing to a filename.

filename :

  Output filename to open and write to

Returns :

  new raptor_iostream object or NULL on failure

raptor_new_iostream_to_filename

### raptor_new_iostream_to_file_handle ()

    raptor_iostream* raptor_new_iostream_to_file_handle
                                                (FILE *handle);

Constructor - create a new iostream writing to a FILE*.

The handle must already be open for writing. NOTE: This does not fclose the handle when it is finished.

handle :

  FILE* handle to write to

Returns :

  new raptor_iostream object or NULL on failure

raptor_new_iostream_to_file_handle

### raptor_new_iostream_to_string ()

    raptor_iostream* raptor_new_iostream_to_string
                                                (void **string_p,
                                                 size_t *length_p,
                                                 void* (*malloc_handler) (size_t size));

Constructor - create a new iostream writing to a string.

If malloc_handler is null, raptor will allocate it using it's own memory allocator. *string_p is set to NULL on failure (and *length_p to 0 if length_p is not NULL).

string_p :

  pointer to location to hold string

length_p :

  pointer to location to hold length of string (or NULL)

malloc_handler :

  pointer to malloc to use to make string (or NULL)

Returns :

  new raptor_iostream object or NULL on failure

raptor_new_iostream_to_string

### raptor_free_iostream ()

    void        raptor_free_iostream            (raptor_iostream *iostr);

Destructor - destroy an iostream.

iostr :

  iostream object

raptor_free_iostream

### raptor_iostream_write_bytes ()

    int         raptor_iostream_write_bytes     (raptor_iostream *iostr,
                                                 const void *ptr,
                                                 size_t size,
                                                 size_t nmemb);

Write bytes to the iostream.

iostr :

  raptor iostream

ptr :

  start of objects to write

size :

  size of object

nmemb :

  number of objects

Returns :

  number of objects written or less than nmemb or 0 on failure

raptor_iostream_write_bytes

### raptor_iostream_write_byte ()

    int         raptor_iostream_write_byte      (raptor_iostream *iostr,
                                                 const int byte);

Write a byte to the iostream.

iostr :

  raptor iostream

byte :

  byte to write

Returns :

  non-0 on failure

raptor_iostream_write_byte

### raptor_iostream_write_end ()

    void        raptor_iostream_write_end       (raptor_iostream *iostr);

End writing to the iostream.

iostr :

  raptor iostream

raptor_iostream_write_end

### raptor_iostream_write_string ()

    int         raptor_iostream_write_string    (raptor_iostream *iostr,
                                                 const void *string);

Write a NULL-terminated string to the iostream.

iostr :

  raptor iostream

string :

  string

Returns :

  non-0 on failure

raptor_iostream_write_string

### raptor_iostream_write_counted_string ()

    int         raptor_iostream_write_counted_string
                                                (raptor_iostream *iostr,
                                                 const void *string,
                                                 size_t len);

Write a counted string to the iostream.

iostr :

  raptor iostream

string :

  string

len :

  string length

Returns :

  non-0 on failure

raptor_iostream_write_counted_string

### raptor_iostream_get_bytes_written_count ()

    size_t      raptor_iostream_get_bytes_written_count
                                                (raptor_iostream *iostr);

Get the number of bytes written to the iostream.

iostr :

  raptor iostream

Returns :

  number of bytes written or 0 if non written so far

raptor_iostream_get_bytes_written_count

### raptor_iostream_write_decimal ()

    int         raptor_iostream_write_decimal   (raptor_iostream *iostr,
                                                 int integer);

Write an integer in decimal to the iostream.

iostr :

  raptor iostream

integer :

  integer to format as decimal

Returns :

  non-0 on failure

raptor_iostream_write_decimal

### raptor_iostream_format_hexadecimal ()

    int         raptor_iostream_format_hexadecimal
                                                (raptor_iostream *iostr,
                                                 unsigned int integer,
                                                 int width);

Write an integer in hexadecimal to the iostream.

Always 0-fills the entire field and writes in uppercase A-F

iostr :

  raptor iostream

integer :

  unsigned integer to format as hexadecimal

width :

  field width

Returns :

  non-0 on failure

raptor_iostream_format_hexadecimal

### raptor_iostream_write_stringbuffer ()

    int         raptor_iostream_write_stringbuffer
                                                (raptor_iostream *iostr,
                                                 raptor_stringbuffer *sb);

Write a stringbuffer to an iostream.

iostr :

  raptor iostream

sb :

  raptor_stringbuffer to write

Returns :

  non-0 on failure

raptor_iostream_write_stringbuffer

### raptor_iostream_write_string_ntriples ()

    int         raptor_iostream_write_string_ntriples
                                                (raptor_iostream *iostr,
                                                 unsigned char *string,
                                                 size_t len,
                                                 const char delim);

Write an UTF-8 string using N-Triples escapes to an iostream.

iostr :

  raptor_iostream to write to

string :

  UTF-8 string to write

len :

  length of UTF-8 string

delim :

  Terminating delimiter character for string (such as " or >) or \0 for no escaping.

Returns :

  non-0 on failure such as bad UTF-8 encoding.

raptor_iostream_write_string_ntriples

### raptor_iostream_write_statement_ntriples ()

    void        raptor_iostream_write_statement_ntriples
                                                (raptor_iostream *iostr,
                                                 const raptor_statement *statement);

Write a raptor_statement formatted in N-Triples format to a raptor_iostream

iostr :

  raptor iosteram

statement :

  statement to write

raptor_iostream_write_statement_ntriples