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import bindings/quickjs
import js/jserror
import js/javascript
import js/jstypes
import chagashi/charset
import chagashi/decoder
import chagashi/decodercore
import chagashi/validator
import chagashi/validatorcore
type
JSTextEncoder = ref object
JSTextDecoder = ref object
encoding: Charset
ignoreBOM {.jsget.}: bool
fatal {.jsget.}: bool
doNotFlush: bool
bomSeen: bool
td: TextDecoder
tv: ref TextValidatorUTF8
validateBuf: seq[uint8]
jsDestructor(JSTextDecoder)
jsDestructor(JSTextEncoder)
type TextDecoderOptions = object of JSDict
fatal: bool
ignoreBOM: bool
func newJSTextDecoder(label = "utf-8", options = TextDecoderOptions()):
JSResult[JSTextDecoder] {.jsctor.} =
let encoding = getCharset(label)
if encoding in {CHARSET_UNKNOWN, CHARSET_REPLACEMENT}:
return err(newRangeError("Invalid encoding label"))
return ok(JSTextDecoder(
ignoreBOM: options.ignoreBOM,
fatal: options.fatal,
td: if encoding != CHARSET_UTF_8: newTextDecoder(encoding) else: nil,
tv: if encoding == CHARSET_UTF_8: (ref TextValidatorUTF8)() else: nil,
encoding: encoding
))
type Growbuf = object
p: ptr UncheckedArray[uint8]
cap: int
len: int
{.warning[Deprecated]: off.}:
proc `=destroy`(growbuf: var Growbuf) =
if growbuf.p != nil:
dealloc(growbuf.p)
growbuf.p = nil
const BufferSize = 128
proc grow(buf: var Growbuf) =
if buf.cap == 0:
buf.cap = BufferSize
else:
buf.cap *= 2
buf.p = cast[ptr UncheckedArray[uint8]](buf.p.realloc(buf.cap))
proc write(buf: var Growbuf; s: openArray[uint8]) =
if buf.len + s.len > buf.cap:
buf.grow()
if s.len > 0:
copyMem(addr buf.p[buf.len], unsafeAddr s[0], s.len)
buf.len += s.len
proc write(buf: var Growbuf; s: string) =
if buf.len + s.len > buf.cap:
buf.grow()
if s.len > 0:
copyMem(addr buf.p[buf.len], unsafeAddr s[0], s.len)
buf.len += s.len
proc decode0(this: JSTextDecoder; ctx: JSContext; input: JSArrayBufferView;
stream: bool): JSResult[JSValue] =
var oq = Growbuf(
p: cast[ptr UncheckedArray[uint8]](alloc(BufferSize)),
len: 0,
cap: BufferSize
)
var i = 0
let H = int(input.abuf.len) - 1
template handle_error =
if this.fatal:
return errTypeError("Failed to decode string")
oq.write("\uFFFD")
i = this.td.i
while true:
case this.td.decode(input.abuf.p.toOpenArray(i, H),
oq.p.toOpenArray(0, oq.cap - 1), oq.len)
of tdrDone:
if not stream:
case this.td.finish()
of tdfrDone: discard
of tdfrError: handle_error
break
of tdrError:
handle_error
of tdrReqOutput:
oq.grow()
return ok(JS_NewStringLen(ctx, cast[cstring](oq.p), csize_t(oq.len)))
proc validate0(this: JSTextDecoder; ctx: JSContext; input: JSArrayBufferView;
stream: bool): JSResult[JSValue] =
# assume input is valid; do not allocate yet
var oq = Growbuf(p: nil, len: 0, cap: 0)
var i = 0
let H = int(input.abuf.len) - 1
var n = 0
template handle_error =
if this.fatal:
return errTypeError("Failed to decode string")
# write from previous error (or beginning) to the last valid char
oq.write(input.abuf.p.toOpenArray(i, n))
oq.write("\uFFFD")
this.validateBuf.setLen(0)
i = this.tv.i
while true:
case this.tv[].validate(input.abuf.p.toOpenArray(i, H), n)
of tvrDone:
break
of tvrError:
handle_error
if not stream:
case this.tv[].finish()
of tvrDone: discard
of tvrError: handle_error
if this.validateBuf.len > 0 and n > -1:
oq.write(this.validateBuf)
oq.write(input.abuf.p.toOpenArray(i, n))
this.validateBuf.setLen(0)
this.validateBuf.add(input.abuf.p.toOpenArray(n + 1, input.abuf.high))
if oq.len > 0:
assert oq.p != nil
return ok(JS_NewStringLen(ctx, cast[cstring](oq.p), csize_t(oq.len)))
assert oq.p == nil
return ok(JS_NewStringLen(ctx, cast[cstring](input.abuf.p), csize_t(n + 1)))
type TextDecodeOptions = object of JSDict
stream: bool
#TODO AllowSharedBufferSource
proc decode(ctx: JSContext; this: JSTextDecoder;
input = none(JSArrayBufferView); options = TextDecodeOptions()):
JSResult[JSValue] {.jsfunc.} =
if not this.doNotFlush:
if this.td != nil:
this.td = newTextDecoder(this.encoding)
else:
assert this.tv != nil
this.tv = (ref TextValidatorUTF8)()
this.bomSeen = false
if this.doNotFlush != options.stream:
this.doNotFlush = options.stream
if input.isSome:
if this.td != nil:
return this.decode0(ctx, input.get, options.stream)
else:
assert this.encoding == CHARSET_UTF_8
# just validate
return this.validate0(ctx, input.get, options.stream)
return ok(JS_NewString(ctx, ""))
func jencoding(this: JSTextDecoder): string {.jsfget: "encoding".} =
return $this.encoding
func newTextEncoder(): JSTextEncoder {.jsctor.} =
return JSTextEncoder()
func jencoding(this: JSTextEncoder): string {.jsfget: "encoding".} =
return "utf-8"
proc dealloc_wrap(rt: JSRuntime; opaque, p: pointer) {.cdecl.} =
dealloc(p)
proc encode(this: JSTextEncoder; input = ""): JSUint8Array {.jsfunc.} =
# we have to validate input first :/
#TODO it is possible to do less copies here...
var input = input.toValidUTF8()
let buf = cast[ptr UncheckedArray[uint8]](alloc(input.len))
copyMem(buf, addr input[0], input.len)
let abuf = JSArrayBuffer(
p: buf,
len: csize_t(input.len),
dealloc: dealloc_wrap
)
return JSUint8Array(
abuf: abuf,
offset: 0,
nmemb: csize_t(input.len)
)
#TODO encodeInto
proc addEncodingModule*(ctx: JSContext) =
ctx.registerType(JSTextDecoder, name = "TextDecoder")
ctx.registerType(JSTextEncoder, name = "TextEncoder")
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