From: Ralph Ronnquist <ralph.ronnquist@gmail.com>
Date: Tue, 18 May 2021 04:46:56 +0000 (+1000)
Subject: expand to handle core block based streams
X-Git-Url: https://git.rrq.au/?a=commitdiff_plain;h=ce86ed5b6ba71fe9f33774a41429e5f96e991be6;p=rrq%2Frrqforth.git

expand to handle core block based streams
---

diff --git a/stdio.asm b/stdio.asm
index fed8eda..f94b0cc 100644
--- a/stdio.asm
+++ b/stdio.asm
@@ -17,59 +17,78 @@
 	jmp sys_mmap_asm	; exit via sys_mmap
 
 ;;; ========================================
-;;; Mapping files
-
-	;; ( fd -- address )
-	;; Request memory mapping of a file
-	WORD p_mmap,'MMAP',fasm
-	pushr rsi		; pretend it's a FORTH word since it
-				; ends via sys_mmap_asm
-	pop rax
-	push qword 0		; address of mapping (suggestion)
-	push qword 10240	; length of mapping
-	push qword 1		; protection mode PROT_READ
-	push qword 2		; flags MAP_PRIVATE
-	push rax		; fd
-	push qword 0		; offset
-	jmp sys_mmap_asm	; exit via sys_mmap
-
-;;; ========================================
-;;; Input stream handling. An input stream has a stream buffer that is
+;;; Input stream handling.
+;;;
+;;; An input stream for a file descriptor has a stream buffer that is
 ;;; gradually filled on needs basis. The stream buffer includes a
 ;;; header portion with:
 ;;; * size of buffer (excluding the 32 byte head)
-;;; * source file descriptor
+;;; * source file descriptor (or -1 for pure in-core data)
 ;;; * current fill
 ;;; * current read position
+;;;
+;;; An input stream for a memory block as a "detached" stream head
+;;; with:
+;;; * block address
+;;; * -1
+;;; * size of block
+;;; * current read position (starts at 8 = after block size)
 
-	WORD p_stream,'STREAM',
-	;; ( fd size -- addr )
+	WORD p_stream,'STREAM',fasm
+	;; ( fd size -- addr ) or ( block -1 -- addr )
 	;; Allocates a stream buffer of the given size and initializes
 	;; it to be filled from the given input file descriptor.
-	dq p_dup		; ( fd size size )
-	dq p_malloc		; ( fd size addr )
-	dq p_2dup		; ( fd size addr size addr )
-	dq p_swap		; ( fd size addr addr size )
-	dq p_erase		; ( fd size addr )
-	ENDFORTH
-	pop rax			; ( fd size )
-	pop rbx			; ( fd )
-	sub rbx,32
+	pushr rsi
+	mov rax,[rsp]
+	cmp rax,-1
+	je p_stream_MEM
+	push rax
+	DOFORTH p_malloc	; ( fd size addr )
+	push qword [rsp]
+	push qword [rsp+16]	; ( fd size addr addr size )
+	DOFORTH p_erase		; ( fd size addr )
+	pop rax			; addr ( fd size )
+	pop rbx			; size ( fd )
+	sub rbx,32		; reduce by header size
 	mov [rax],rbx
 	pop rbx
 	mov [rax+8],rbx
 	push rax
 	jmp exit
 
+p_stream_MEM:
+	push 32			; size of detached header (wastefull?)
+	DOFORTH p_malloc	; ( block addr )
+	pop rax			; header address
+	pop rbx			; block address
+	mov rcx,[rbx]		; block content size (excludes size field)
+	add rbx,8		; block content address
+	mov qword [rax],rbx	; save block content address
+	mov qword [rax+8],-1	; -1 = memblock flag
+	mov qword [rax+16],rcx	; save block content size
+	mov qword [rax+24],0	; current position
+	push rax
+	jmp exit
+
+;;; ========================================
+;;; Stream reading
+;;; READ-STREAM-CHAR ( stream -- ch )
+	
 	WORD p_read_stream_char,'READ-STREAM-CHAR',fasm
 	;; ( stream -- ch )
 	pushr rsi
 	mov rax,qword [rsp]
 	mov rbx,[rax+16]	; fill
+
 p_read_stream_char.READ:
 	mov rcx,[rax+24]	; current
 	cmp rbx,rcx
 	jg p_read_stream_char.CHAR
+
+	;; pull in more from the source, if any
+	cmp qword [rax+8],-1	; fd == -1 for "no source"
+	je p_read_stream_char.EOF
+	
 	push qword [rax+8] 	; fd
 	lea rbx,[rax+32]
 	push rbx		; buffer
@@ -83,10 +102,12 @@ p_read_stream_char.READ:
 	jle p_read_stream_char.EOF
 	mov qword[rax+16],rbx
 	jmp p_read_stream_char.READ
+
 p_read_stream_char.EOF:
 	mov qword [rsp],-1
 	popr rsi
 	next
+
 p_read_stream_char.CHAR:
 	inc qword [rax+24]
 	add rcx,32
@@ -96,16 +117,19 @@ p_read_stream_char.CHAR:
 	popr rsi
 	next
 
-	WORD p_line_buffer,'LINE-BUFFER',dovariable
-	;; A buffer for holding a text line
+;;; ========================================
+;;; Input handling
+
+	WORD p_pad,'PAD',dovariable
+	;; A buffer for holding a word
 	rb 1024
 
 	WORD p_read_word,'READ-WORD',fasm
-	;; ( stream -- addr length )
-	;; Read a text line from the stream into the line buffer
+	;; ( stream -- char* length )
+	;; Read next word from the given stream into the PAD
 	pushr rsi
 	pop rax
-	push qword p_line_buffer_DFA
+	push qword p_pad_DFA
 	push qword 0
 	push rax