pdfParser · @awacloud/pdf

Typed PDF objects, ISO 32000-2 §7.3 — token stream → { type, value/items/entries } tree.

Module pdfParser | Source packages/front/office/pdf/src/syntax/parser.js | Deps pdfErrors, pdfParserObj, pdfTokenizer | Worker-safe yes

Produces the typed objects null, bool, int, real, name, string, array, dict, ref, stream. The <int> <int> R form is recognised speculatively as a ref. Indirect definitions <num> <gen> obj … endobj are read by parseIndirect, which promotes dict + stream into { type: 'stream', dict, raw }. The parser validates neither xref integrity nor /Length — that is the document layer's job.

The module re-exposes the injected pdfTokenizer's tokenize and the whole pdfParserObj surface (obj, getEntry, isType) so a consumer needs a single resolve to go from bytes to a typed tree.

Resolve

const parser = runtime.resolve('pdfParser');
// Returns: { tokenize, parseObject, parseIndirect, parseFromBytes,
//            parseIndirectFromBytes, parserLimits, setParserLimits,
//            obj, getEntry, isType }

API

Member	Signature	Returns
`tokenize`	`(bytes: Uint8Array, opts?) => Tokenizer`	Re-export of `pdfTokenizer.tokenize`.
`parseObject`	`(tok: Tokenizer) => PdfObject`	One typed object.
`parseIndirect`	`(tok: Tokenizer, resolveRef?) => { num, gen, value }`	Full indirect definition.
`parseFromBytes`	`(bytes: Uint8Array) => PdfObject`	Helper — tokenize then `parseObject`.
`parseIndirectFromBytes`	`(bytes: Uint8Array, at: number, resolveRef?) => { num, gen, value }`	Offset helper.
`parserLimits`	`{ maxDepth, maxArrayLen, maxStreamBytes }`	Live, mutable per-instance guard-rails.
`setParserLimits`	`(partial) => parserLimits`	Merges positive integer overrides and returns the updated object.
`obj`	builders	Primitive constructors (see below).
`getEntry`	`(dict, key: string) => PdfObject \| undefined`	Lookup on `{type:'dict'}`.
`isType`	`(v, kind: string) => boolean`	Test `v.type === kind`.

`parserLimits` defaults

Key	Default	Guards
`maxDepth`	`200`	Nesting depth — `pdf/parser/depth-exceeded`.
`maxArrayLen`	`1_000_000`	Array element count — `pdf/parser/array-too-long`.
`maxStreamBytes`	`268_435_456` (256 MiB)	Stream payload quota during `parseIndirect`.

Only positive integers are accepted; anything else is ignored, so setParserLimits({}) is a no-op that simply returns the current limits.

`obj` builders

Helper	Signature
`obj.nul()`	`→ { type: 'null' }`
`obj.bool(v)`	`→ { type: 'bool', value }`
`obj.int(v)`	`→ { type: 'int', value }`
`obj.real(v)`	`→ { type: 'real', value }`
`obj.name(s)`	`→ { type: 'name', value }`
`obj.string(bytes, syntax?)`	`syntax ∈ 'lit'\|'hex'`
`obj.array(items?)`
`obj.dict(entries?)`
`obj.ref(num, gen?)`
`obj.stream(dict, raw)`

Token → type mapping

Token	Output type
`kw 'null'/'true'/'false'`	`null` / `bool`
`name`	`name`
`string`	`string` (`syntax:'lit'`)
`hex`	`string` (`syntax:'hex'`)
`int` + `int` + `kw 'R'`	`ref`
`int`	`int`
`real`	`real`
`open_arr … close_arr`	`array`
`open_dict … close_dict`	`dict`
`dict` + `kw 'stream'` (via `parseIndirect`)	`stream`

Examples

Parse a standalone object

const parser = runtime.resolve('pdfParser');
const o = parser.parseFromBytes(new TextEncoder().encode('<< /Size 6 /Root 1 0 R >>'));
o.type;                            // 'dict'
parser.getEntry(o, 'Size').value;  // 6
parser.getEntry(o, 'Root');        // { type: 'ref', num: 1, gen: 0 }

Read an indirect definition carrying a stream

const tok = parser.tokenize(bytes, { start: offset });
const def = parser.parseIndirect(tok, ref => doc._raw.resolve(ref));
def.value.type;            // 'stream'
def.value.raw;             // Uint8Array

Tighten the limits for untrusted input

parser.setParserLimits({ maxDepth: 32, maxStreamBytes: 8 * 1024 * 1024 });
parser.parserLimits.maxDepth;   // 32

Build with `obj`

const o = parser.obj.dict({
    Type: parser.obj.name('Catalog'),
    Pages: parser.obj.ref(2, 0)
});

Errors

Code	Class	When
`pdf/parser/eof`	`ParseError`	End of stream during `parseObject`.
`pdf/parser/unexpected-keyword`	`ParseError`	Unrecognised keyword in object position.
`pdf/parser/unexpected-token`	`ParseError`	Foreign token (e.g. a lone `n`).
`pdf/parser/unbalanced`	`ParseError`	`]` or `>>` without an opener.
`pdf/parser/unterminated-array`	`ParseError`	`[` never closed.
`pdf/parser/unterminated-dict`	`ParseError`	`<<` never closed.
`pdf/parser/dict-key-not-name`	`ParseError`	Dictionary key is not a name.
`pdf/parser/depth-exceeded`	`ParseError`	Nesting deeper than `parserLimits.maxDepth`.
`pdf/parser/array-too-long`	`ParseError`	Array longer than `parserLimits.maxArrayLen`.
`pdf/parser/indirect-bad-num` / `-bad-gen` / `-missing-obj` / `-missing-endobj`	`ParseError`	Malformed `<n> <g> obj … endobj`.
`pdf/parser/stream/no-endstream`	`ParseError`	`endstream` not found.
`pdf/parser/stream/expected-endstream`	`ParseError`	Something else found instead.