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A fork of https://github.com/crosspoint-reader/crosspoint-reader
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2.9 kB · 85 lines
C++
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586#include "NextBookFinder.h"
#include <FsHelpers.h>#include <HalStorage.h>#include <Logging.h>#include <Memory.h>
#include <algorithm>#include <string_view>
#include "CrossPointSettings.h"
namespace {constexpr size_t NAME_BUFFER_SIZE = 500;
bool isSupportedBookFile(const std::string_view name) { // Formats ReaderActivity can open (bmp is a viewer, not a book, so it is excluded) return FsHelpers::hasEpubExtension(name) || FsHelpers::hasXtcExtension(name) || FsHelpers::hasTxtExtension(name) || FsHelpers::hasMarkdownExtension(name);}} // namespace
std::vector<std::string> NextBookFinder::findNextBooks(const std::string& currentBookPath, const size_t maxCount) { std::vector<std::string> result; if (maxCount == 0 || currentBookPath.empty()) { return result; }
const std::string folder = FsHelpers::extractFolderPath(currentBookPath); const auto lastSlash = currentBookPath.find_last_of('/'); const std::string currentName = lastSlash == std::string::npos ? currentBookPath : currentBookPath.substr(lastSlash + 1);
auto dir = Storage.open(folder.c_str()); if (!dir || !dir.isDirectory()) { LOG_ERR("NBF", "Cannot open folder: %s", folder.c_str()); return result; } dir.rewindDirectory();
const auto nameBuffer = makeUniqueNoThrow<char[]>(NAME_BUFFER_SIZE); if (!nameBuffer) { LOG_ERR("NBF", "OOM: %d bytes", static_cast<int>(NAME_BUFFER_SIZE)); dir.close(); return result; }
// Heap use is bounded: at most maxCount+1 short filename strings live at once (the // file browser holds a whole folder in the same std::string form). A failed // allocation here would abort like any STL growth in this codebase; the reserve // below makes vector growth a single up-front allocation. result.reserve(maxCount + 1); const auto less = [](const std::string& a, const std::string& b) { return FsHelpers::naturalLess(a, b); };
for (auto file = dir.openNextFile(); file; file = dir.openNextFile()) { if (file.isDirectory()) { continue; } file.getName(nameBuffer.get(), NAME_BUFFER_SIZE); if (!SETTINGS.showHiddenFiles && nameBuffer[0] == '.') { continue; } if (!isSupportedBookFile(nameBuffer.get())) { continue; } std::string name{nameBuffer.get()}; // Keep only files ordering strictly after the current one; equal names (the book // itself, or a case-variant of it) compare "not less" both ways and drop out here. if (!FsHelpers::naturalLess(currentName, name)) { continue; } // Bounded insertion sort: keep the maxCount lowest-ordering candidates if (result.size() >= maxCount && !less(name, result.back())) { continue; } const auto pos = std::lower_bound(result.begin(), result.end(), name, less); result.insert(pos, std::move(name)); if (result.size() > maxCount) { result.pop_back(); } } dir.close();
return result;}