Public Access
twislaandClaude Sonnet 5.5
b0e8226943
A streaming JSON scanner (a 33 KB list of releases costs a few hundred bytes), the release reader built on it, HTTP response heads and chunked bodies, URLs, and the decisions: which release is an update, whether to announce it, and which download URLs the device takes. Tested against the real answers of git.twis.la. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT
58 lines
1.9 KiB
C++
58 lines
1.9 KiB
C++
#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <functional>
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#include <string>
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#include <vector>
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namespace roro::release {
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// Reads JSON as it arrives, a chunk at a time, and reports each plain value (a string, a number,
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// true, false, null) with where it was found: "tag_name", "assets[1].name", "[2].draft". Nothing
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// is kept but the path, so a 33 KB list of releases costs a few hundred bytes. A value longer than
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// `maxValueBytes` is cut (never in the middle of a character) and reported as truncated.
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// Meant for a server's answer, not for validating JSON: it only refuses what it can't follow.
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class JsonScanner {
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public:
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using Sink = std::function<void(const std::string& path, const std::string& value, bool isString, bool truncated)>;
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explicit JsonScanner(Sink sink, size_t maxValueBytes = 300) : sink_(std::move(sink)), max_(maxValueBytes) {}
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void feed(const char* data, size_t len);
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bool failed() const { return failed_; }
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bool done() const { return done_ && !failed_; } // the top-level value is complete
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private:
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enum class Expect : uint8_t { Value, KeyOrEnd, Colon, CommaOrEnd };
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struct Frame {
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bool isObject;
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std::string key;
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int index;
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};
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void step(char c);
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void startString(bool key);
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void stringChar(char c);
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void appendCodePoint(uint32_t cp);
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void endString();
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void endLiteral();
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void valueDone();
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void append(const char* bytes, size_t n);
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std::string path() const;
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void fail() { failed_ = true; }
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Sink sink_;
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size_t max_;
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std::vector<Frame> stack_;
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Expect expect_ = Expect::Value;
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bool inString_ = false, isKey_ = false, escape_ = false, inLiteral_ = false;
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int unicodeLeft_ = 0;
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uint32_t unicode_ = 0, highSurrogate_ = 0;
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bool truncated_ = false;
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std::string text_;
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bool failed_ = false, done_ = false;
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};
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} // namespace roro::release
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