Introduces StreamReader to accumulate socket data delivered in arbitrary chunks into one buffer, so a Parser can build an object (a line, a header block, a MIME boundary) that spans any number of packets without losing its place. Parser is redesigned around this: no longer inherits MString (was redundant with its own buffer member), takes a StreamReader&, and drives a resumable COMPLETE/INCOMPLETE/DATA_AVAIL state-machine protocol via doParse(). LineParser, IMFHeader, and IMFBoundary are rewritten as real, working resumable parsers against the shared buffer instead of the previous non-compiling stubs (mismatched constructors/return types, a syntax error, checkParse() never implemented). IMFFormData is left as the stub it already was, just restored to compiling against the new IMFHeader signature - fully wiring it up needs IMFMultipart/IMFText migrated to StreamReader too, out of scope here. Verified with real runtime tests (not just compilation) covering data split mid-line, mid-CRLF, mid-header-fold, and mid-boundary-marker across separate feed() calls, plus StreamReader::compact(). Along the way fixed a header-value bug (space after ':' wasn't skipped) and a double cursor-offset subtraction bug in two places caused by forgetting that ZString::getLength() is already cursor-relative, not the raw buffer size. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
83 lines
2.7 KiB
C++
83 lines
2.7 KiB
C++
#ifndef __Parser_h__
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#define __Parser_h__
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#include "StreamReader.h"
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namespace coreutils {
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///
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/// Parser is the base class for building a protocol/object parser that reads
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/// from a shared StreamReader's buffer. A subclass implements parse() as a
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/// resumable state machine (typically a switch on an internal state member)
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/// that consumes as much of the buffer as it currently can and reports how
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/// the parse should proceed via Status:
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///
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/// - COMPLETE: the object this Parser builds is fully parsed and ready.
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/// - INCOMPLETE: not enough data is currently buffered to make more
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/// progress; the caller should wait for more data
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/// (StreamReader::feed()) before calling doParse() again.
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/// The subclass's state member must reflect exactly where
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/// parsing should resume - and must NOT have consumed any
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/// cursor position it can't yet commit to (see individual
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/// Parser subclasses for how they guarantee this).
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/// - DATA_AVAIL: this call made progress and there is more buffered data
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/// this Parser can still work through right now, without
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/// waiting for new data to arrive.
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///
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/// Call doParse() (not parse() directly) to drive a Parser - it loops on
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/// DATA_AVAIL automatically and returns once the result is COMPLETE or
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/// INCOMPLETE.
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///
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class Parser {
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public:
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Parser(StreamReader &reader);
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enum class Status {
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COMPLETE,
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INCOMPLETE,
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DATA_AVAIL
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};
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virtual ~Parser();
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///
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/// doParse is the entry and re-entry point method to continue the
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/// parsing process. Safe to call repeatedly (e.g. once per
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/// StreamReader::feed()) - each call resumes exactly where the
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/// previous one left off.
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///
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Status doParse();
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///
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/// Inside of parse() you can call another parser object with the
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/// checkParse method to attempt parsing with a candidate sub-parser
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/// sharing the same StreamReader. Returns true only once that
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/// sub-parser fully completes - retain the same sub-parser instance
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/// across re-entries into your own parse() (e.g. as a member) so it
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/// can resume, rather than constructing a new one on every call.
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///
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bool checkParse(Parser &parser);
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protected:
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///
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/// parse() performs one resumable step of parsing against reader's
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/// buffer. Must be implemented by every concrete Parser to build its
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/// specific object.
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///
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virtual Status parse() = 0;
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StreamReader &reader;
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};
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}
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#endif
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