class Oj::StreamWriter

Supports building a JSON document one element at a time. Build the IO stream document by pushing values into the document. Pushing an array or an object will create that element in the JSON document and subsequent pushes will add the elements to that array or object until a pop() is called.

Public Class Methods

new(io, options) click to toggle source

Creates a new StreamWriter. Options are supported according the specified mode or the mode in the default options. Note that if mimic_JSON or Oj.optimize_rails has not been called then the behavior of the modes may not be the same as if they were.

In addition to the regular dump options for the various modes a :buffer_size option is available. It should be set to a positive integer. It is considered a hint of how large the initial internal buffer should be and also a hint on when to flush.

  • io [IO] stream to write to

  • options [Hash] formatting options

static VALUE stream_writer_new(int argc, VALUE *argv, VALUE self) {
    StreamWriterType type   = STREAM_IO;
    int              fd     = 0;
    VALUE            stream = argv[0];
    VALUE            clas   = rb_obj_class(stream);
    StreamWriter     sw;
#if !IS_WINDOWS
    VALUE s;
#endif

    if (oj_stringio_class == clas) {
        type = STRING_IO;
#if !IS_WINDOWS
    } else if (rb_respond_to(stream, oj_fileno_id) && Qnil != (s = rb_funcall(stream, oj_fileno_id, 0)) &&
               0 != (fd = FIX2INT(s))) {
        type = FILE_IO;
#endif
    } else if (rb_respond_to(stream, oj_write_id)) {
        type = STREAM_IO;
    } else {
        rb_raise(rb_eArgError, "expected an IO Object.");
    }
    sw = OJ_R_ALLOC(struct _streamWriter);
    if (2 == argc && T_HASH == rb_type(argv[1])) {
        volatile VALUE v;
        int            buf_size = 0;

        if (Qundef == buffer_size_sym) {
            buffer_size_sym = ID2SYM(rb_intern("buffer_size"));
            rb_gc_register_address(&buffer_size_sym);
        }
        if (Qnil != (v = rb_hash_lookup(argv[1], buffer_size_sym))) {
            if (rb_cInteger != rb_obj_class(v)) {
                OJ_R_FREE(sw);
                rb_raise(rb_eArgError, ":buffer size must be a Integer.");
            }
            buf_size = FIX2INT(v);
        }
        oj_str_writer_init(&sw->sw, buf_size);
        oj_parse_options(argv[1], &sw->sw.opts);
        sw->flush_limit = buf_size;
    } else {
        oj_str_writer_init(&sw->sw, 4096);
        sw->flush_limit = 0;
    }
    sw->sw.out.indent = sw->sw.opts.indent;
    sw->stream        = stream;
    sw->type          = type;
    sw->fd            = fd;

    return Data_Wrap_Struct(oj_stream_writer_class, 0, stream_writer_free, sw);
}

Public Instance Methods

flush() click to toggle source

Flush any remaining characters in the buffer.

static VALUE stream_writer_flush(VALUE self) {
    stream_writer_write((StreamWriter)DATA_PTR(self));

    return Qnil;
}
pop() click to toggle source

Pops up a level in the JSON document closing the array or object that is currently open.

static VALUE stream_writer_pop(VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    oj_str_writer_pop(&sw->sw);
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}
pop_all() click to toggle source

Pops all level in the JSON document closing all the array or object that is currently open.

static VALUE stream_writer_pop_all(VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    oj_str_writer_pop_all(&sw->sw);
    stream_writer_write(sw);

    return Qnil;
}
push_array(key=nil) click to toggle source

Pushes an array onto the JSON document. Future pushes will be to this object until a pop() is called.

  • key [String] the key if adding to an object in the JSON document

static VALUE stream_writer_push_array(int argc, VALUE *argv, VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    switch (argc) {
    case 0: oj_str_writer_push_array(&sw->sw, 0); break;
    case 1:
        if (Qnil == argv[0]) {
            oj_str_writer_push_array(&sw->sw, 0);
        } else {
            oj_str_writer_push_array(&sw->sw, StringValuePtr(argv[0]));
        }
        break;
    default: rb_raise(rb_eArgError, "Wrong number of argument to 'push_object'."); break;
    }
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}
push_json(value, key=nil) click to toggle source

Pushes a string onto the JSON document. The String must be a valid JSON encoded string. No additional checking is done to verify the validity of the string.

  • value [Object] value to add to the JSON document

  • key [String] the key if adding to an object in the JSON document

static VALUE stream_writer_push_json(int argc, VALUE *argv, VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    switch (argc) {
    case 1: oj_str_writer_push_json((StrWriter)DATA_PTR(self), StringValuePtr(*argv), 0); break;
    case 2:
        if (Qnil == argv[1]) {
            oj_str_writer_push_json((StrWriter)DATA_PTR(self), StringValuePtr(*argv), 0);
        } else {
            oj_str_writer_push_json((StrWriter)DATA_PTR(self), StringValuePtr(*argv), StringValuePtr(argv[1]));
        }
        break;
    default: rb_raise(rb_eArgError, "Wrong number of argument to 'push_json'."); break;
    }
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}
push_key(key) click to toggle source

Pushes a key onto the JSON document. The key will be used for the next push if currently in a JSON object and ignored otherwise. If a key is provided on the next push then that new key will be ignored.

  • key [String] the key pending for the next push

static VALUE stream_writer_push_key(VALUE self, VALUE key) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    oj_str_writer_push_key(&sw->sw, StringValuePtr(key));
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}
push_object(key=nil) click to toggle source

Pushes an object onto the JSON document. Future pushes will be to this object until a pop() is called.

  • key [String] the key if adding to an object in the JSON document

static VALUE stream_writer_push_object(int argc, VALUE *argv, VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    switch (argc) {
    case 0: oj_str_writer_push_object(&sw->sw, 0); break;
    case 1:
        if (Qnil == argv[0]) {
            oj_str_writer_push_object(&sw->sw, 0);
        } else {
            oj_str_writer_push_object(&sw->sw, StringValuePtr(argv[0]));
        }
        break;
    default: rb_raise(rb_eArgError, "Wrong number of argument to 'push_object'."); break;
    }
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}
push_value(value, key=nil) click to toggle source

Pushes a value onto the JSON document.

  • value [Object] value to add to the JSON document

  • key [String] the key if adding to an object in the JSON document

static VALUE stream_writer_push_value(int argc, VALUE *argv, VALUE self) {
    StreamWriter sw = (StreamWriter)DATA_PTR(self);

    switch (argc) {
    case 1: oj_str_writer_push_value((StrWriter)DATA_PTR(self), *argv, 0); break;
    case 2:
        if (Qnil == argv[1]) {
            oj_str_writer_push_value((StrWriter)DATA_PTR(self), *argv, 0);
        } else {
            oj_str_writer_push_value((StrWriter)DATA_PTR(self), *argv, StringValuePtr(argv[1]));
        }
        break;
    default: rb_raise(rb_eArgError, "Wrong number of argument to 'push_value'."); break;
    }
    if (sw->flush_limit < sw->sw.out.cur - sw->sw.out.buf) {
        stream_writer_write(sw);
    }
    return Qnil;
}