fasmg-include/interface/writer.inc

; vim:ft=fasm:

;include 'utils.inc'
;include 'align.inc'
;include 'struct.inc'
;include 'interface.inc'

;if ~ defined Writer

interface Writer
	write buf, size
end interface


struct _Buffer
	data dq ?
	size dq ?
	capacity dq ?
ends
struct BufferedWriter.data
	buf _Buffer
	writer dq ?
ends

BufferedWriter.buffer_size = (byte * 0x1000 * 0x80)
proc BufferedWriter.write
	.self = r15
	.self.data = r14
	.new_size = r13
	.old_size = r12
	.buf = rdi
	.len = rsi

	using_regs .self, .self.data, .new_size, .old_size
		mov .self, rax
		interface.self_data .self, .self.data

		.check_size:
			mov .old_size, [.self.data + BufferedWriter.data.buf.size]
			lea .new_size, [.old_size + .len]
			cmp [.self.data + BufferedWriter.data.buf.capacity], .new_size
			jge .capcity_ok

		.capcity_exceeded:
			mov rax, .self
			using_regs .len, .buf
				call BufferedWriter.flush ; TODO: check fail
			end using_regs
			cmp [.self.data + BufferedWriter.data.buf.capacity], .len
			jge .check_size
			.write_too_big:
				using_regs .len, .buf
					Writer.write [.self.data + BufferedWriter.data.writer], .buf, .len
				end using_regs
				jmp .end_reg

		.capcity_ok:
			mov rdx, .len
			.len = rdx

			mov rsi, .buf
			.buf = rsi

			mov rax, [.self.data +  BufferedWriter.data.buf.data]
			lea rdi, [rax + .old_size]
			memcpy rdi, .buf, .len
			mov [.self.data + BufferedWriter.data.buf.size], .new_size
		
		.end_reg:
	end using_regs

end proc


proc BufferedWriter.flush
	.self_data = r15
	using_regs .self_data
		interface.self_data rax, .self_data
		Writer.write [.self_data + BufferedWriter.data.writer], [.self_data + BufferedWriter.data.buf.data], [.self_data + BufferedWriter.data.buf.size]
		mov qword [.self_data + BufferedWriter.data.buf.size], 0
	end using_regs
end proc


proc FDWriter.write
	.buf = rsi
	.len = rdx

	mov .len, rsi
	mov .buf, rdi

	interface.self_data rax
	write dword [rax], .buf, .len
end proc

;include 'stdlib.inc'

;end if