Add catalog-backed book cover extraction support

Implement cover extraction for books stored in catalog.fibc omnibus format to avoid loading large (~400KB) book arenas into RAM. Uses catalog's pre-resolved cover entries with minimal memory footprint (~42KB resident). Includes arena management for catalog opening and ZIP entry extraction with configurable scratch buffers.
This commit is contained in:
Justin Mitchell
2026-07-08 13:51:58 -04:00
parent 9bb488dc86
commit e3f2e27078
+195 -4
View File
@@ -1,5 +1,6 @@
#include "BookCoverUtils.h"
#include <BookCatalog.h>
#include <FreeInkBook.h>
#include <FsHelpers.h>
#include <HalStorage.h>
@@ -21,8 +22,10 @@ namespace {
using EpubReaderUtils::cacheDirForBook;
using freeink::book::Arena;
using freeink::book::Book;
using freeink::book::BookCatalog;
using freeink::book::BookStatus;
using freeink::book::ManifestItem;
using freeink::book::ZipEntry;
using freeink::book::ZipEntryReader;
// Container open is transient: metadata + ZIP catalog only, freed on return.
@@ -70,6 +73,167 @@ bool withOpenBook(const std::string& epubPath, Fn&& fn) {
return fn(book, source, scratch);
}
// --- Catalog-backed (omnibus) path -----------------------------------------
// Books whose container index lives in catalog.fibc can never take the
// Book::open path above: their in-RAM book arena would need ~400 KB (King's
// Avatar: 419,630 B). The catalog keeps only ~42 KB resident and resolved
// the cover entry at build time, so cover work opens the catalog instead.
constexpr size_t kCatalogOpenScratch = 4096; // fingerprint scan buffer
// ZipEntryReader deflate state: 8.4 KB tinfl decompressor + 32 KB window +
// 2 KB input buffer + arena alignment (~43.3 KB measured). The 4 KB copy
// buffer is allocated separately so the contiguous requirement stays well
// under the ~49 KB max block a post-render Home heap was measured to offer.
constexpr size_t kExtractScratchIdeal = 48 * 1024;
constexpr size_t kExtractScratchFloor = 44 * 1024;
constexpr size_t kExtractIoBufSize = 4096;
std::string catalogPathForDir(const std::string& cacheDir) { return cacheDir + "/" + BookCatalog::kCatalogName; }
// Opens an existing catalog.fibc with an exactly-sized resident arena and
// runs fn(catalog). Both arenas are freed when this returns, so callers that
// stream from the container afterwards get that heap back first. A stale or
// corrupt catalog fails soft: the reader activity owns rebuilds, and cover
// work simply retries after the next book open refreshes the index.
template <typename Fn>
bool withOpenCatalog(const std::string& epubPath, const std::string& cacheDir, freeink::book::BookSource& source,
Fn&& fn) {
SdCacheStorage cache;
cache.setDir(cacheDir.c_str());
size_t resident = 0;
if (BookCatalog::residentBytes(cache, &resident) != BookStatus::Ok) {
LOG_ERR("COVER", "Catalog footer unreadable: %s", epubPath.c_str());
return false;
}
auto bookBuf = makeUniqueNoThrow<uint8_t[]>(resident);
auto scratchBuf = makeUniqueNoThrow<uint8_t[]>(kCatalogOpenScratch);
if (!bookBuf || !scratchBuf) {
LOG_ERR("COVER", "OOM: catalog arena (%u B, max block %u)", static_cast<unsigned>(resident),
static_cast<unsigned>(heap_caps_get_largest_free_block(MALLOC_CAP_8BIT)));
return false;
}
Arena bookArena(bookBuf.get(), resident);
Arena scratch(scratchBuf.get(), kCatalogOpenScratch);
BookCatalog catalog;
const BookStatus st = catalog.open(source, cache, bookArena, scratch);
if (st != BookStatus::Ok) {
LOG_ERR("COVER", "Catalog open failed: %d (%s)", static_cast<int>(st), epubPath.c_str());
return false;
}
return fn(catalog);
}
// Streams a catalog-resolved cover entry to `tempPath`. The inflate scratch
// is sized from the largest free block (Home-screen heaps can be down to a
// ~49 KB max block); when even the floor cannot be met this fails soft and
// the caller's retry path picks it up next visit. The leading magic bytes
// tell JPEG (FFD8) from PNG (89504E47); anything else sets `unsupportedOut`
// so the caller can cache the coverless verdict. Runs with the catalog
// arenas already freed: the deflate state and the resident tables cannot
// coexist on a fragmented heap.
bool extractCoverEntry(freeink::book::BookSource& source, const ZipEntry& entry, const std::string& tempPath,
bool* jpegOut, bool* unsupportedOut) {
*unsupportedOut = false;
auto ioBuf = makeUniqueNoThrow<uint8_t[]>(kExtractIoBufSize);
size_t scratchSize = 16; // stored entries need no inflate state
if (entry.method != 0) { // deflated: full inflate state
const size_t block = heap_caps_get_largest_free_block(MALLOC_CAP_8BIT);
scratchSize = std::min(kExtractScratchIdeal, block > kAllocSlack ? block - kAllocSlack : 0);
if (scratchSize < kExtractScratchFloor) {
LOG_ERR("COVER", "OOM: cover inflate scratch (want %u B, max block %u)",
static_cast<unsigned>(kExtractScratchFloor), static_cast<unsigned>(block));
return false;
}
}
auto scratchBuf = makeUniqueNoThrow<uint8_t[]>(scratchSize);
if (!ioBuf || !scratchBuf) {
LOG_ERR("COVER", "OOM: cover extract scratch (%u B)", static_cast<unsigned>(scratchSize));
return false;
}
Arena scratch(scratchBuf.get(), scratchSize);
uint8_t* buf = ioBuf.get();
ZipEntryReader reader;
if (reader.open(source, entry, scratch) != BookStatus::Ok) return false;
bool ok = true;
bool jpeg = false;
bool sniffed = false;
{
HalFile out;
if (!Storage.openFileForWrite("COVER", tempPath, out)) return false;
for (;;) {
const int32_t n = reader.read(buf, kExtractIoBufSize);
if (n < 0) {
ok = false;
break;
}
if (n == 0) break;
if (!sniffed && n >= 4) {
jpeg = buf[0] == 0xFF && buf[1] == 0xD8;
const bool png = buf[0] == 0x89 && buf[1] == 0x50 && buf[2] == 0x4E && buf[3] == 0x47;
if (!jpeg && !png) {
*unsupportedOut = true; // format will not improve on retry
ok = false;
break;
}
sniffed = true;
}
if (out.write(buf, n) != static_cast<size_t>(n)) {
ok = false;
break;
}
}
// `out` closes at scope exit, before the converter reopens the path.
}
ok = ok && sniffed;
if (!ok) Storage.remove(tempPath.c_str());
*jpegOut = jpeg;
return ok;
}
// Cover resolution + extraction for a catalog-backed book. Returns "opened"
// semantics matching withOpenBook: true when the catalog opened and the
// coverless verdict is trustworthy, false on any transient failure.
bool extractCatalogCover(const std::string& epubPath, const std::string& cacheDir, std::string& tempPathOut,
bool& jpegOut, bool& coverlessOut) {
SdBookSource source;
if (!source.open(epubPath.c_str())) {
LOG_ERR("COVER", "Cannot open: %s", epubPath.c_str());
return false;
}
ZipEntry cover;
bool haveCover = false;
const bool opened = withOpenCatalog(epubPath, cacheDir, source, [&](BookCatalog& catalog) {
haveCover = catalog.coverEntry(&cover);
cover.name = ""; // pointed into the catalog arena, which is freed on return
return true;
});
if (!opened) return false;
if (!haveCover) {
LOG_DBG("COVER", "No cover image in catalog: %s", epubPath.c_str());
coverlessOut = true;
return true;
}
const std::string extractPath = cacheDir + "/.cover.img";
bool unsupported = false;
bool jpeg = false;
if (!extractCoverEntry(source, cover, extractPath, &jpeg, &unsupported)) {
if (unsupported) {
LOG_ERR("COVER", "Unsupported cover format in catalog: %s", epubPath.c_str());
coverlessOut = true; // permanent: cache the coverless verdict
}
// Otherwise transient (OOM, SD hiccup): leave tempPathOut empty so the
// caller's "will retry" path handles it next visit.
return true;
}
jpegOut = jpeg;
tempPathOut = extractPath;
return true;
}
const ManifestItem* findCoverItem(const Book& book) {
for (size_t m = 0; m < book.manifestCount(); ++m) {
const ManifestItem* item = book.manifestItem(m);
@@ -137,9 +301,16 @@ bool extractItem(const Book& book, freeink::book::BookSource& source, Arena& scr
// usable cover — the one case callers may cache negatively; every other
// failure is potentially transient (OOM, SD hiccup) and worth retrying.
//
// The conversion runs AFTER withOpenBook returns: extraction needs the book
// arenas (~95 KB), the JPEG/PNG decoder needs ~53 KB of its own, and the
// heap cannot hold both at once — the temp file is the handoff between them.
// The conversion runs AFTER the container source (Book arenas or catalog +
// inflate scratch) is fully freed: extraction needs ~50-95 KB, the JPEG/PNG
// decoder needs ~53 KB of its own, and the heap cannot hold both at once --
// the temp file is the handoff between them.
//
// When catalog.fibc exists (SD-backed omnibus index built by the reader),
// the cover comes through the catalog instead of Book::open; the in-RAM
// book arena for such containers can never fit at the home screen. When no
// catalog exists this NEVER builds one -- small books open in RAM fine, and
// catalog builds belong to the reader activity.
template <typename ConvertFn>
bool generateFromCover(const std::string& epubPath, const std::string& outPath, ConvertFn&& convert,
bool* coverlessOut) {
@@ -150,7 +321,11 @@ bool generateFromCover(const std::string& epubPath, const std::string& outPath,
bool coverless = false;
bool jpeg = false;
std::string tempPath;
const bool opened = withOpenBook(epubPath, [&](Book& book, freeink::book::BookSource& source, Arena& scratch) {
bool opened;
if (Storage.exists(catalogPathForDir(cacheDir).c_str())) {
opened = extractCatalogCover(epubPath, cacheDir, tempPath, jpeg, coverless);
} else {
opened = withOpenBook(epubPath, [&](Book& book, freeink::book::BookSource& source, Arena& scratch) {
const ManifestItem* cover = findCoverItem(book);
if (cover == nullptr) {
LOG_DBG("COVER", "No cover image in manifest: %s", epubPath.c_str());
@@ -169,6 +344,7 @@ bool generateFromCover(const std::string& epubPath, const std::string& outPath,
if (extractItem(book, source, scratch, *cover, extractPath)) tempPath = extractPath;
return true;
});
}
bool converted = false;
if (opened && !tempPath.empty()) {
@@ -261,6 +437,21 @@ bool generateThumbBmp(const std::string& epubPath, const int height) {
}
bool readMetadata(const std::string& epubPath, std::string* titleOut, std::string* authorOut) {
const std::string cacheDir = cacheDirForBook(epubPath);
if (Storage.exists(catalogPathForDir(cacheDir).c_str())) {
// Catalog-backed omnibus: title/author are resident in the catalog, so
// this stays within the ~42 KB arena instead of Book::open's ~400 KB.
SdBookSource source;
if (!source.open(epubPath.c_str())) {
LOG_ERR("COVER", "Cannot open: %s", epubPath.c_str());
return false;
}
return withOpenCatalog(epubPath, cacheDir, source, [&](BookCatalog& catalog) {
if (titleOut != nullptr) *titleOut = catalog.metadata().title;
if (authorOut != nullptr) *authorOut = catalog.metadata().author;
return true; // strings copied while the catalog arena is live
});
}
return withOpenBook(epubPath, [&](Book& book, freeink::book::BookSource&, Arena&) {
if (titleOut != nullptr) *titleOut = book.metadata().title;
if (authorOut != nullptr) *authorOut = book.metadata().author;