Xteink-X4-crosspoint-reader/lib/OpdsParser/OpdsParser.h
KasyanDiGris 47ef92e8fd
fix: OPDS browser OOM (#403)
## Summary

- Rewrite OpdsParser to stream parsing instead of full content
- Fix OOM due to big http xml response

Closes #385 

---

### AI Usage

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Did you use AI tools to help write this code? _**NO**_
2026-01-22 01:43:51 +11:00

105 lines
2.5 KiB
C++

#pragma once
#include <Print.h>
#include <expat.h>
#include <string>
#include <vector>
/**
* Type of OPDS entry.
*/
enum class OpdsEntryType {
NAVIGATION, // Link to another catalog
BOOK // Downloadable book
};
/**
* Represents an entry from an OPDS feed (either a navigation link or a book).
*/
struct OpdsEntry {
OpdsEntryType type = OpdsEntryType::NAVIGATION;
std::string title;
std::string author; // Only for books
std::string href; // Navigation URL or epub download URL
std::string id;
};
// Legacy alias for backward compatibility
using OpdsBook = OpdsEntry;
/**
* Parser for OPDS (Open Publication Distribution System) Atom feeds.
* Uses the Expat XML parser to parse OPDS catalog entries.
*
* Usage:
* OpdsParser parser;
* if (parser.parse(xmlData, xmlLength)) {
* for (const auto& entry : parser.getEntries()) {
* if (entry.type == OpdsEntryType::BOOK) {
* // Downloadable book
* } else {
* // Navigation link to another catalog
* }
* }
* }
*/
class OpdsParser final : public Print {
public:
OpdsParser();
~OpdsParser();
// Disable copy
OpdsParser(const OpdsParser&) = delete;
OpdsParser& operator=(const OpdsParser&) = delete;
size_t write(uint8_t) override;
size_t write(const uint8_t*, size_t) override;
void flush() override;
bool error() const;
operator bool() { return !error(); }
/**
* Get the parsed entries (both navigation and book entries).
* @return Vector of OpdsEntry entries
*/
const std::vector<OpdsEntry>& getEntries() const& { return entries; }
std::vector<OpdsEntry> getEntries() && { return std::move(entries); }
/**
* Get only book entries (legacy compatibility).
* @return Vector of book entries
*/
std::vector<OpdsEntry> getBooks() const;
/**
* Clear all parsed entries.
*/
void clear();
private:
// Expat callbacks
static void XMLCALL startElement(void* userData, const XML_Char* name, const XML_Char** atts);
static void XMLCALL endElement(void* userData, const XML_Char* name);
static void XMLCALL characterData(void* userData, const XML_Char* s, int len);
// Helper to find attribute value
static const char* findAttribute(const XML_Char** atts, const char* name);
XML_Parser parser = nullptr;
std::vector<OpdsEntry> entries;
OpdsEntry currentEntry;
std::string currentText;
// Parser state
bool inEntry = false;
bool inTitle = false;
bool inAuthor = false;
bool inAuthorName = false;
bool inId = false;
bool errorOccured = false;
};