Method: FFI::AbstractMemory#put_bytes

Defined in:
ext/ffi_c/AbstractMemory.c

#put_bytes(offset, str, index = 0, length = nil) ⇒ self

Put a string in memory.

Parameters:

  • offset (Integer) —

    point in buffer to start from

  • str (String) —

    string to put to memory

  • index (Integer)
  • length (Integer) —

    string’s length in bytes. If nil, a (memory size - offset) length string is returned).

Returns:

  • (self)

Raises:

  • (IndexError) —

    if length is too great

  • (NullPointerError) —

    if memory not initialized

  • (RangeError) —

    if index is negative, or if index+length is greater than size of string

  • (SecurityError) —

    when writing unsafe string to memory



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# File 'ext/ffi_c/AbstractMemory.c', line 572

static VALUE
memory_put_bytes(int argc, VALUE* argv, VALUE self)
{
    AbstractMemory* ptr = MEMORY(self);
    VALUE offset = Qnil, str = Qnil, rbIndex = Qnil, rbLength = Qnil;
    long off, len, idx;
    int nargs = rb_scan_args(argc, argv, "22", &offset, &str, &rbIndex, &rbLength);

    Check_Type(str, T_STRING);

    off = NUM2LONG(offset);
    idx = nargs > 2 ? NUM2LONG(rbIndex) : 0;
    if (idx < 0) {
        rb_raise(rb_eRangeError, "index cannot be less than zero");
        return Qnil;
    }
    len = nargs > 3 ? NUM2LONG(rbLength) : (RSTRING_LEN(str) - idx);
    if ((idx + len) > RSTRING_LEN(str)) {
        rb_raise(rb_eRangeError, "index+length is greater than size of string");
        return Qnil;
    }

    checkWrite(ptr);
    checkBounds(ptr, off, len);

    memcpy(ptr->address + off, RSTRING_PTR(str) + idx, len);

    return self;
}