Files
Crosspoint/lib/KOReaderSync/ProgressMapper.cpp
T
2026-07-04 21:21:24 +03:00

904 lines
31 KiB
C++

#include "ProgressMapper.h"
#include <GfxRenderer.h>
#include <Logging.h>
#include <algorithm>
#include <cmath>
#include <cstring>
#include "ChapterXPathResolver.h"
#include "Epub/Section.h"
#include "Epub/htmlEntities.h"
#include "Utf8.h"
namespace {
int parseIndex(const std::string& xpath, const char* prefix, bool last = false) {
const size_t prefixLen = strlen(prefix);
const size_t pos = last ? xpath.rfind(prefix) : xpath.find(prefix);
if (pos == std::string::npos) return -1;
const size_t numStart = pos + prefixLen;
const size_t numEnd = xpath.find(']', numStart);
if (numEnd == std::string::npos || numEnd == numStart) return -1;
int val = 0;
for (size_t i = numStart; i < numEnd; i++) {
if (xpath[i] < '0' || xpath[i] > '9') return -1;
val = val * 10 + (xpath[i] - '0');
}
return val;
}
int parseCharOffset(const std::string& xpath) {
const size_t textPos = xpath.rfind("text()");
const size_t dotPos = (textPos != std::string::npos) ? xpath.find('.', textPos) : xpath.rfind('.');
if (dotPos == std::string::npos || dotPos + 1 >= xpath.size()) return 0;
int val = 0;
for (size_t i = dotPos + 1; i < xpath.size(); i++) {
if (xpath[i] < '0' || xpath[i] > '9') return 0;
val = val * 10 + (xpath[i] - '0');
}
return val;
}
// Parse the N from text()[N] in the XPath (1-based; defaults to 1 if absent or 1).
int parseTextNodeIndex(const std::string& xpath) {
const size_t textPos = xpath.rfind("text()[");
if (textPos == std::string::npos) return 1;
const size_t numStart = textPos + 7; // strlen("text()[")
const size_t numEnd = xpath.find(']', numStart);
if (numEnd == std::string::npos || numEnd == numStart) return 1;
int val = 0;
for (size_t i = numStart; i < numEnd; i++) {
if (xpath[i] < '0' || xpath[i] > '9') return 1;
val = val * 10 + (xpath[i] - '0');
}
return val > 0 ? val : 1;
}
bool isChapterStartXPath(const std::string& xpath) {
if (xpath.find("/p[") != std::string::npos || xpath.find("/li[") != std::string::npos) {
return false;
}
static constexpr char kDocFragment[] = "/body/DocFragment[";
const size_t docFragPos = xpath.find(kDocFragment);
if (docFragPos == std::string::npos) {
return false;
}
const size_t docFragEnd = xpath.find(']', docFragPos + strlen(kDocFragment));
if (docFragEnd == std::string::npos) {
return false;
}
if (docFragEnd + 1 == xpath.size()) {
return true;
}
if (xpath[docFragEnd + 1] == '.') {
if (docFragEnd + 2 >= xpath.size()) {
return false;
}
for (size_t i = docFragEnd + 2; i < xpath.size(); i++) {
if (xpath[i] != '0') return false;
}
return true;
}
static constexpr char kDocBody[] = "]/body";
const size_t docBodyPos = xpath.find(kDocBody);
if (docBodyPos == std::string::npos) {
return false;
}
size_t bodyContentStart = docBodyPos + strlen(kDocBody);
if (bodyContentStart == xpath.size()) {
return true;
}
if (xpath[bodyContentStart] != '/') {
return false;
}
bodyContentStart++;
if (bodyContentStart == xpath.size()) {
return true;
}
const size_t dotPos = xpath.rfind('.');
if (dotPos == std::string::npos || dotPos <= bodyContentStart || dotPos + 1 >= xpath.size()) {
return false;
}
size_t terminalEnd = dotPos;
static constexpr char kTextNode[] = "/text()";
const size_t textNodePos = xpath.rfind(kTextNode, dotPos);
if (textNodePos != std::string::npos && textNodePos >= bodyContentStart) {
terminalEnd = textNodePos;
}
if (xpath.find('/', bodyContentStart) < terminalEnd) {
return false;
}
for (size_t i = dotPos + 1; i < xpath.size(); i++) {
if (xpath[i] != '0') return false;
}
return true;
}
// Parsed representation of one step in the XPath ancestry.
struct XPathStep {
char tag[12]; // element name, null-terminated
int siblingIndex; // 1-based sibling index, or 0 if unspecified (treat as 1)
};
static constexpr int MAX_XPATH_DEPTH = 16;
// Parse the XPath segment between /body/DocFragment[N]/body/ and the terminal position
// into an ordered sequence of steps. Returns step count, 0 on failure.
// Example input: "/body/DocFragment[1]/body/div[1]/ul/li[4]/text()[1].51"
// Fills steps with: {div,1}, {ul,1}, {li,4}
int parseXPathSteps(const std::string& xpath, XPathStep steps[MAX_XPATH_DEPTH]) {
static const char kBodyFrag[] = "/body/DocFragment[";
const size_t fragPos = xpath.find(kBodyFrag);
if (fragPos == std::string::npos) return 0;
const size_t afterBracket = xpath.find(']', fragPos + strlen(kBodyFrag));
if (afterBracket == std::string::npos) return 0;
static const char kBody[] = "/body/";
if (xpath.compare(afterBracket + 1, strlen(kBody), kBody) != 0) return 0;
size_t pos = afterBracket + 1 + strlen(kBody);
size_t stepsEnd = xpath.rfind("/text()");
if (stepsEnd == std::string::npos) {
stepsEnd = xpath.rfind('.');
if (stepsEnd == std::string::npos || stepsEnd <= pos || stepsEnd + 1 >= xpath.size()) return 0;
for (size_t i = stepsEnd + 1; i < xpath.size(); i++) {
if (xpath[i] < '0' || xpath[i] > '9') return 0;
}
}
if (stepsEnd <= pos) return 0;
int count = 0;
while (pos < stepsEnd && count < MAX_XPATH_DEPTH) {
const size_t slash = xpath.find('/', pos);
const size_t segEnd = (slash < stepsEnd) ? slash : stepsEnd;
XPathStep& step = steps[count];
const size_t bracket = xpath.find('[', pos);
const size_t nameEnd = (bracket != std::string::npos && bracket < segEnd) ? bracket : segEnd;
const size_t nameLen = nameEnd - pos;
if (nameLen == 0 || nameLen >= sizeof(step.tag)) return 0;
memcpy(step.tag, xpath.c_str() + pos, nameLen);
step.tag[nameLen] = '\0';
if (bracket != std::string::npos && bracket < segEnd) {
const size_t closeBracket = xpath.find(']', bracket + 1);
if (closeBracket == std::string::npos || closeBracket > segEnd) return 0;
int idx = 0;
for (size_t i = bracket + 1; i < closeBracket; i++) {
if (xpath[i] < '0' || xpath[i] > '9') return 0;
idx = idx * 10 + (xpath[i] - '0');
}
step.siblingIndex = idx;
} else {
step.siblingIndex = 1;
}
count++;
pos = (slash < stepsEnd) ? slash + 1 : stepsEnd;
}
return count;
}
class ParagraphStreamer final : public Print {
size_t bytesWritten = 0;
bool globalInTag = false;
bool globalInEntity = false;
static constexpr size_t MAX_ENTITY_SIZE = 16;
char entityBuffer[MAX_ENTITY_SIZE] = {};
size_t entityLen = 0;
// Forward mode: count <p> paragraphs at a byte offset (legacy, used by generateXPath)
size_t fwdTarget;
int fwdResult = 0;
bool fwdCaptured = false;
// Reverse mode shared state
int revChar;
bool revPFound = false;
bool revDone = false;
int revVisChars = 0;
size_t totalVisChars = 0;
size_t targetVisChars = 0;
// --- Legacy reverse mode (paragraph index only, no ancestry) ---
int revParagraph = 0;
int pCount = 0;
int paragraphAtMatch = 0;
int liCount = 0;
int liCountAtMatch = 0;
int targetTextNode = 1;
int currentTextNode = 0;
int paragraphHtmlDepth = -1;
// --- Ancestry-aware reverse mode ---
const XPathStep* steps = nullptr;
int stepCount = 0;
int siblingCounters[MAX_XPATH_DEPTH] = {};
bool insideStep[MAX_XPATH_DEPTH] = {};
int htmlDepth = 0;
int stepEnteredAtDepth[MAX_XPATH_DEPTH] = {};
// Tag name accumulation
enum TagParseState { TAG_IDLE, TAG_IN_NAME, TAG_ATTRS } tagState = TAG_IDLE;
bool tagIsClose = false;
char tagName[12] = {};
int tagNameLen = 0;
int matchedDepth = 0;
// Anchor ID capture
static constexpr int MAX_ANCHOR_ID = 64;
char capturedAnchorId[MAX_ANCHOR_ID] = {};
int capturedAnchorIdLen = 0;
bool capturingAnchorTag = false;
enum AnchorAttrState {
ATTR_FIND_NAME,
ATTR_READ_NAME,
ATTR_AFTER_NAME,
ATTR_BEFORE_VALUE,
ATTR_CAPTURE_D,
ATTR_CAPTURE_S
} attrState = ATTR_FIND_NAME;
uint8_t attrNameLen = 0;
bool currentAttrIsId = false;
bool inAttrQuote =
false; // true while inside a quoted attribute value (prevents '/' from being treated as self-close)
char attrQuoteChar = 0;
uint8_t nonVisibleDepth = 0;
bool isNonVisibleTag() const {
return strcasecmp(tagName, "head") == 0 || strcasecmp(tagName, "style") == 0 ||
strcasecmp(tagName, "script") == 0 || strcasecmp(tagName, "title") == 0;
}
static bool isAttrWhitespace(uint8_t c) { return c == ' ' || c == '\t' || c == '\n' || c == '\r'; }
static bool isAttrNameChar(uint8_t c) {
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9') || c == '_' || c == '-' ||
c == ':' || c == '.';
}
void resetAnchorAttrScan() {
attrState = ATTR_FIND_NAME;
attrNameLen = 0;
currentAttrIsId = false;
}
void finishCapturedAnchorId() {
capturedAnchorId[capturedAnchorIdLen] = '\0';
capturingAnchorTag = false;
resetAnchorAttrScan();
}
void beginAnchorIdScan() {
capturingAnchorTag = true;
resetAnchorAttrScan();
}
void endAnchorIdScan() {
if (capturingAnchorTag) {
capturedAnchorIdLen = 0;
}
capturingAnchorTag = false;
resetAnchorAttrScan();
}
void appendCapturedAnchorId(uint8_t c) {
if (capturedAnchorIdLen + 1 < MAX_ANCHOR_ID) {
capturedAnchorId[capturedAnchorIdLen++] = c;
}
}
void scanAnchorAttribute(uint8_t c) {
switch (attrState) {
case ATTR_FIND_NAME:
if (isAttrNameChar(c)) {
attrState = ATTR_READ_NAME;
attrNameLen = 1;
currentAttrIsId = c == 'i';
}
break;
case ATTR_READ_NAME:
if (isAttrNameChar(c)) {
if (attrNameLen == 1) {
currentAttrIsId = currentAttrIsId && c == 'd';
} else {
currentAttrIsId = false;
}
attrNameLen++;
} else {
currentAttrIsId = currentAttrIsId && attrNameLen == 2;
if (isAttrWhitespace(c)) {
attrState = ATTR_AFTER_NAME;
} else if (c == '=') {
attrState = ATTR_BEFORE_VALUE;
} else {
resetAnchorAttrScan();
}
}
break;
case ATTR_AFTER_NAME:
if (isAttrWhitespace(c)) {
break;
}
if (c == '=') {
attrState = ATTR_BEFORE_VALUE;
} else if (isAttrNameChar(c)) {
attrState = ATTR_READ_NAME;
attrNameLen = 1;
currentAttrIsId = c == 'i';
} else {
resetAnchorAttrScan();
}
break;
case ATTR_BEFORE_VALUE:
if (isAttrWhitespace(c)) {
break;
}
if (currentAttrIsId && c == '"') {
capturedAnchorIdLen = 0;
attrState = ATTR_CAPTURE_D;
} else if (currentAttrIsId && c == '\'') {
capturedAnchorIdLen = 0;
attrState = ATTR_CAPTURE_S;
} else if (c == '"') {
attrState = ATTR_CAPTURE_D;
} else if (c == '\'') {
attrState = ATTR_CAPTURE_S;
} else {
resetAnchorAttrScan();
}
break;
case ATTR_CAPTURE_D:
if (c == '"') {
if (currentAttrIsId) {
finishCapturedAnchorId();
} else {
resetAnchorAttrScan();
}
} else if (currentAttrIsId) {
appendCapturedAnchorId(c);
}
break;
case ATTR_CAPTURE_S:
if (c == '\'') {
if (currentAttrIsId) {
finishCapturedAnchorId();
} else {
resetAnchorAttrScan();
}
} else if (currentAttrIsId) {
appendCapturedAnchorId(c);
}
break;
}
}
void onVisibleCodepoint() {
totalVisChars++;
if (revPFound && !revDone) {
// Ancestry mode: count only while inside the fully-matched element and in the target text node.
// Legacy mode: count only while still inside the matched paragraph and in the target text node.
const bool inTargetNode = (stepCount > 0) ? (matchedDepth == stepCount && currentTextNode == targetTextNode)
: (paragraphHtmlDepth >= 0 && currentTextNode == targetTextNode);
if (inTargetNode) {
revVisChars++;
if (revVisChars >= revChar) {
targetVisChars = totalVisChars;
revDone = true;
}
}
}
}
void onVisibleText(const char* text) {
if (!text) return;
const unsigned char* ptr = reinterpret_cast<const unsigned char*>(text);
while (*ptr != 0) {
utf8NextCodepoint(&ptr);
onVisibleCodepoint();
}
}
void flushEntityAsLiteral() {
for (size_t i = 0; i < entityLen; i++) onVisibleCodepoint();
}
void finishEntity() {
entityBuffer[entityLen] = '\0';
const char* resolved = lookupHtmlEntity(entityBuffer, entityLen);
if (resolved)
onVisibleText(resolved);
else
flushEntityAsLiteral();
globalInEntity = false;
entityLen = 0;
}
void onLegacyP() {
pCount++;
if (!revPFound && revParagraph > 0 && pCount >= revParagraph) {
revPFound = true;
revVisChars = 0;
paragraphHtmlDepth = htmlDepth;
currentTextNode = 1;
if (revChar <= 0 && targetTextNode <= 1) {
targetVisChars = totalVisChars;
revDone = true;
}
}
}
void onOpenTag() {
htmlDepth++;
if (nonVisibleDepth > 0 || isNonVisibleTag()) {
nonVisibleDepth++;
return;
}
if (stepCount == 0) {
if (strcasecmp(tagName, "p") == 0) onLegacyP();
return;
}
// Capture a child <a id> inside the fully-matched element even after target char is found.
if (revPFound && matchedDepth == stepCount && capturedAnchorIdLen == 0 && strcasecmp(tagName, "a") == 0) {
beginAnchorIdScan();
}
if (revDone) return;
if (strcasecmp(tagName, "p") == 0) pCount++;
if (strcasecmp(tagName, "li") == 0) liCount++;
if (matchedDepth < stepCount) {
const XPathStep& target = steps[matchedDepth];
if (strcasecmp(tagName, target.tag) == 0) {
// Count only direct children of the previously matched ancestor step.
// For step 0 any depth is valid; subsequent steps must be exactly one level deeper.
const bool atCorrectDepth = (matchedDepth == 0) || (htmlDepth == stepEnteredAtDepth[matchedDepth - 1] + 1);
if (!atCorrectDepth) return;
siblingCounters[matchedDepth]++;
if (siblingCounters[matchedDepth] == target.siblingIndex) {
insideStep[matchedDepth] = true;
stepEnteredAtDepth[matchedDepth] = htmlDepth;
matchedDepth++;
if (matchedDepth == stepCount) {
beginAnchorIdScan();
paragraphAtMatch = pCount;
liCountAtMatch = liCount;
revPFound = true;
capturedAnchorIdLen = 0;
revVisChars = 0;
currentTextNode = 1; // Reset text node counter for this element
if (revChar <= 0 && targetTextNode <= 1) {
targetVisChars = totalVisChars;
revDone = true;
}
}
}
}
}
}
void onCloseTag() {
if (nonVisibleDepth > 0) {
nonVisibleDepth--;
if (htmlDepth > 0) htmlDepth--;
return;
}
// Legacy mode: each direct child element closing advances the text node index.
if (stepCount == 0 && revPFound && !revDone && paragraphHtmlDepth >= 0 && htmlDepth == paragraphHtmlDepth + 1) {
currentTextNode++;
if (currentTextNode == targetTextNode && revChar <= 0) {
targetVisChars = totalVisChars;
revDone = true;
}
}
// Legacy mode: stop tracking when the matched paragraph itself closes.
if (stepCount == 0 && revPFound && !revDone && paragraphHtmlDepth >= 0 && htmlDepth == paragraphHtmlDepth) {
revPFound = false;
paragraphHtmlDepth = -1;
}
// Ancestry mode: advance text node when a direct child of the fully-matched element closes.
if (stepCount > 0 && matchedDepth == stepCount && revPFound && !revDone) {
const int elementDepth = stepEnteredAtDepth[stepCount - 1];
if (htmlDepth == elementDepth + 1) {
currentTextNode++;
if (currentTextNode == targetTextNode && revChar <= 0) {
targetVisChars = totalVisChars;
revDone = true;
}
}
}
if (stepCount > 0 && matchedDepth > 0) {
const int step = matchedDepth - 1;
if (insideStep[step] && htmlDepth == stepEnteredAtDepth[step]) {
insideStep[step] = false;
matchedDepth--;
// If the fully-matched element just closed without finding the target, abort.
if (matchedDepth < stepCount && revPFound && !revDone) {
revPFound = false;
}
for (int i = matchedDepth + 1; i < stepCount; i++) {
siblingCounters[i] = 0;
insideStep[i] = false;
stepEnteredAtDepth[i] = -1;
}
}
}
if (htmlDepth > 0) htmlDepth--;
}
void processByteInTag(uint8_t c) {
switch (tagState) {
case TAG_IDLE:
if (c == '/') {
tagIsClose = true;
tagState = TAG_IN_NAME;
} else if (c != '!' && c != '?') {
tagIsClose = false;
tagName[0] = static_cast<char>(c);
tagNameLen = 1;
tagState = TAG_IN_NAME;
}
break;
case TAG_IN_NAME:
if (c == '>' || c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '/') {
tagName[tagNameLen] = '\0';
if (tagNameLen > 0) {
if (tagIsClose)
onCloseTag();
else
onOpenTag();
// Self-closing open tag (<br/>). Don't double-fire for close tags (</br/>).
if (c == '/' && !tagIsClose) onCloseTag();
}
tagNameLen = 0;
tagState = (c == '>') ? TAG_IDLE : TAG_ATTRS;
} else if (tagNameLen + 1 < static_cast<int>(sizeof(tagName))) {
tagName[tagNameLen++] = static_cast<char>(c);
}
break;
case TAG_ATTRS:
// Track quoted attribute values so '/' inside them is not mistaken for self-closing.
if (!inAttrQuote) {
if (c == '"' || c == '\'') {
inAttrQuote = true;
attrQuoteChar = c;
}
} else if (c == attrQuoteChar) {
inAttrQuote = false;
attrQuoteChar = 0;
}
if (capturingAnchorTag) {
scanAnchorAttribute(c);
}
// Only treat '/' as self-closing when outside a quoted attribute value.
if (c == '/' && !inAttrQuote) {
endAnchorIdScan();
onCloseTag();
}
break;
}
}
public:
explicit ParagraphStreamer(size_t targetByte) : fwdTarget(targetByte), revChar(0) {
memset(stepEnteredAtDepth, -1, sizeof(stepEnteredAtDepth));
}
ParagraphStreamer(int paragraph, int charOff, int textNodeIdx = 1)
: fwdTarget(SIZE_MAX), revChar(charOff), revParagraph(paragraph), targetTextNode(textNodeIdx) {
memset(stepEnteredAtDepth, -1, sizeof(stepEnteredAtDepth));
}
ParagraphStreamer(const XPathStep* xpathSteps, int xpathStepCount, int charOff, int textNodeIdx = 1)
: fwdTarget(SIZE_MAX),
revChar(charOff),
steps(xpathSteps),
stepCount(xpathStepCount),
targetTextNode(textNodeIdx) {
memset(stepEnteredAtDepth, -1, sizeof(stepEnteredAtDepth));
}
size_t write(uint8_t c) override {
if (!fwdCaptured && bytesWritten >= fwdTarget) {
fwdResult = pCount;
fwdCaptured = true;
}
bytesWritten++;
if (globalInEntity) {
if (entityLen + 1 < MAX_ENTITY_SIZE) {
entityBuffer[entityLen++] = static_cast<char>(c);
} else {
flushEntityAsLiteral();
globalInEntity = false;
entityLen = 0;
}
if (globalInEntity) {
if (c == ';') {
finishEntity();
} else if (c == '<' || c == ' ' || c == '\t' || c == '\n' || c == '\r') {
flushEntityAsLiteral();
globalInEntity = false;
entityLen = 0;
}
}
return 1;
}
if (c == '<') {
globalInTag = true;
tagState = TAG_IDLE;
tagNameLen = 0;
tagIsClose = false;
capturingAnchorTag = false;
resetAnchorAttrScan();
inAttrQuote = false;
attrQuoteChar = 0;
} else if (c == '>') {
if (tagState == TAG_ATTRS) {
endAnchorIdScan();
}
globalInTag = false;
inAttrQuote = false;
if (tagState == TAG_IN_NAME && tagNameLen > 0) {
tagName[tagNameLen] = '\0';
if (tagIsClose)
onCloseTag();
else
onOpenTag();
tagNameLen = 0;
}
tagState = TAG_IDLE;
} else if (globalInTag) {
processByteInTag(c);
} else if (nonVisibleDepth > 0) {
// Ignore head/style/script/title text. KOReader XPaths are body-relative, and CSS text
// should not contribute to intra-spine progress.
} else {
if (c == '&') {
globalInEntity = true;
entityBuffer[0] = '&';
entityLen = 1;
} else {
const bool startsCodepoint = (c & 0xC0) != 0x80;
if (startsCodepoint) onVisibleCodepoint();
}
}
return 1;
}
size_t write(const uint8_t* buffer, size_t size) override {
for (size_t i = 0; i < size; i++) write(buffer[i]);
return size;
}
int paragraphCount() const { return fwdCaptured ? fwdResult : pCount; }
int getParagraphAtMatch() const { return paragraphAtMatch; }
int getListItemAtMatch() const { return liCountAtMatch; }
const char* getCapturedAnchorId() const { return capturedAnchorIdLen > 0 ? capturedAnchorId : nullptr; }
size_t totalBytes() const { return bytesWritten; }
bool found() const { return revDone || revPFound; }
size_t getTotalVisChars() const { return totalVisChars; }
size_t getTargetVisChars() const { return targetVisChars; }
float progress() const {
return totalVisChars > 0 ? static_cast<float>(targetVisChars) / static_cast<float>(totalVisChars) : 0.0f;
}
};
bool streamSpine(const std::shared_ptr<Epub>& epub, int spineIndex, ParagraphStreamer& s) {
const auto href = epub->getSpineItem(spineIndex).href;
return !href.empty() && epub->readItemContentsToStream(href, s, 1024);
}
} // namespace
SavedProgressPosition ProgressMapper::toSavedProgress(const std::shared_ptr<Epub>& epub,
const CrossPointPosition& pos) {
SavedProgressPosition result;
float intra =
(pos.totalPages > 1) ? static_cast<float>(pos.pageNumber) / static_cast<float>(pos.totalPages - 1) : 0.0f;
result.percentage = epub->calculateProgress(pos.spineIndex, intra);
if (pos.hasParagraphIndex && pos.paragraphIndex > 0) {
result.xpath = ChapterXPathResolver::findXPathForParagraph(epub, pos.spineIndex, pos.paragraphIndex);
}
// Fall back to progress-based XPath, then synthetic progress mapping.
if (result.xpath.empty()) {
result.xpath = ChapterXPathResolver::findXPathForProgress(epub, pos.spineIndex, intra);
}
if (result.xpath.empty()) {
result.xpath = generateXPath(epub, pos.spineIndex, intra);
}
LOG_DBG("PM", "-> Progress: spine=%d page=%d/%d %.2f%% %s", pos.spineIndex, pos.pageNumber, pos.totalPages,
result.percentage * 100, result.xpath.c_str());
return result;
}
CrossPointPosition ProgressMapper::toCrossPoint(const std::shared_ptr<Epub>& epub, const SavedProgressPosition& koPos,
GfxRenderer& renderer, int currentSpineIndex,
int totalPagesInCurrentSpine, int fallbackTotalPages) {
CrossPointPosition result{};
const size_t bookSize = epub->getBookSize();
if (bookSize == 0) return result;
const int spineCount = epub->getSpineItemsCount();
const float clampedPercentage = std::max(0.0f, std::min(1.0f, koPos.percentage));
const size_t targetBytes = static_cast<size_t>(static_cast<float>(bookSize) * clampedPercentage);
const int docFrag = parseIndex(koPos.xpath, "/body/DocFragment[");
const int xpathP = parseIndex(koPos.xpath, "/p[", true);
const int xpathChar = parseCharOffset(koPos.xpath);
const int xpathTextNode = parseTextNodeIndex(koPos.xpath);
const int xpathSpine = (docFrag >= 1) ? (docFrag - 1) : -1;
XPathStep xpathSteps[MAX_XPATH_DEPTH];
const int xpathStepCount = parseXPathSteps(koPos.xpath, xpathSteps);
// Use ancestry mode whenever the XPath has a structured path (always more accurate than global counting).
const bool useAncestry = xpathStepCount > 0;
if (xpathSpine >= 0 && xpathSpine < spineCount) {
result.spineIndex = xpathSpine;
} else {
for (int i = 0; i < spineCount; i++) {
if (epub->getCumulativeSpineItemSize(i) >= targetBytes) {
result.spineIndex = i;
break;
}
}
}
const size_t prevCum = (result.spineIndex > 0) ? epub->getCumulativeSpineItemSize(result.spineIndex - 1) : 0;
const size_t spineSize = epub->getCumulativeSpineItemSize(result.spineIndex) - prevCum;
if (result.spineIndex == currentSpineIndex && totalPagesInCurrentSpine > 0) {
result.totalPages = totalPagesInCurrentSpine;
} else if (currentSpineIndex >= 0 && currentSpineIndex < spineCount && totalPagesInCurrentSpine > 0) {
const size_t pc = (currentSpineIndex > 0) ? epub->getCumulativeSpineItemSize(currentSpineIndex - 1) : 0;
const size_t cs = epub->getCumulativeSpineItemSize(currentSpineIndex) - pc;
if (cs > 0)
result.totalPages = std::max(
1, static_cast<int>(totalPagesInCurrentSpine * static_cast<float>(spineSize) / static_cast<float>(cs)));
}
if (result.totalPages <= 0) {
Section tempSection(epub, result.spineIndex, renderer);
if (auto cachedCount = tempSection.getCachedPageCount()) {
result.totalPages = *cachedCount;
} else if (fallbackTotalPages > 0) {
result.totalPages = fallbackTotalPages;
} else {
result.totalPages = 1; // Prevent division by zero and give a fallback
}
}
float intra = 0.0f;
bool resolvedIntra = false;
if (useAncestry) {
ParagraphStreamer s(xpathSteps, xpathStepCount, xpathChar, xpathTextNode);
if (streamSpine(epub, result.spineIndex, s) && s.found()) {
intra = s.progress();
resolvedIntra = true;
const int pAtMatch = s.getParagraphAtMatch();
if (pAtMatch > 0) {
result.paragraphIndex = static_cast<uint16_t>(pAtMatch);
result.hasParagraphIndex = true;
}
if (xpathStepCount > 0 && strcasecmp(xpathSteps[xpathStepCount - 1].tag, "li") == 0) {
const int liAtMatch = s.getListItemAtMatch();
if (liAtMatch > 0) {
result.liIndex = static_cast<uint16_t>(liAtMatch);
result.hasLiIndex = true;
}
}
const char* anchorId = s.getCapturedAnchorId();
if (anchorId) {
strncpy(result.xpathAnchorId, anchorId, sizeof(result.xpathAnchorId) - 1);
}
LOG_DBG("PM", "XPath ancestry(%s[%d])/text()[%d]+%d -> %.1f%% (target=%zu total=%zu p~%d li~%d anchor=%s)",
xpathSteps[xpathStepCount - 1].tag, xpathSteps[xpathStepCount - 1].siblingIndex, xpathTextNode, xpathChar,
intra * 100, s.getTargetVisChars(), s.getTotalVisChars(), pAtMatch,
result.hasLiIndex ? static_cast<int>(result.liIndex) : 0, anchorId ? anchorId : "none");
}
} else if (xpathP > 0) {
ParagraphStreamer s(xpathP, xpathChar, xpathTextNode);
if (streamSpine(epub, result.spineIndex, s) && s.found()) {
intra = s.progress();
resolvedIntra = true;
LOG_DBG("PM", "XPath p[%d]/text()[%d]+%d -> %.1f%% (target=%zu total=%zu)", xpathP, xpathTextNode, xpathChar,
intra * 100, s.getTargetVisChars(), s.getTotalVisChars());
}
}
if (!resolvedIntra && xpathSpine >= 0 && xpathSpine < spineCount && isChapterStartXPath(koPos.xpath)) {
intra = 0.0f;
resolvedIntra = true;
LOG_DBG("PM", "Chapter-start XPath %s -> spine=%d page start", koPos.xpath.c_str(), result.spineIndex);
}
if (!resolvedIntra) {
const size_t bytesIn = (targetBytes > prevCum) ? (targetBytes - prevCum) : 0;
intra = std::max(0.0f, std::min(1.0f, static_cast<float>(bytesIn) / static_cast<float>(spineSize)));
}
result.pageNumber = std::max(
0, std::min(static_cast<int>(intra * static_cast<float>(result.totalPages - 1) + 0.5f), result.totalPages - 1));
LOG_DBG("PM", "<- Progress: %.2f%% %s -> spine=%d page=%d/%d", koPos.percentage * 100, koPos.xpath.c_str(),
result.spineIndex, result.pageNumber, result.totalPages);
// Refine page using section cache LUTs: li index, anchor, or paragraph index.
if (result.hasLiIndex || result.xpathAnchorId[0] != '\0' || result.hasParagraphIndex) {
Section tempSection(epub, result.spineIndex, renderer);
bool refined = false;
if (result.hasLiIndex) {
const auto liPage = tempSection.getPageForListItemIndex(result.liIndex);
if (liPage.has_value()) {
LOG_DBG("PM", "Li index %u -> page %d (was %d)", result.liIndex, *liPage, result.pageNumber);
result.pageNumber = *liPage;
refined = true;
} else {
LOG_DBG("PM", "Li index %u not found in section LUT", result.liIndex);
}
}
if (!refined && result.xpathAnchorId[0] != '\0') {
const auto anchorPage = tempSection.getPageForAnchor(std::string(result.xpathAnchorId));
if (anchorPage.has_value()) {
LOG_DBG("PM", "Anchor '%s' -> page %d (was %d)", result.xpathAnchorId, *anchorPage, result.pageNumber);
result.pageNumber = *anchorPage;
refined = true;
} else {
LOG_DBG("PM", "Anchor '%s' not found in section cache", result.xpathAnchorId);
}
}
if (!refined && result.hasParagraphIndex) {
const auto paragraphPage = tempSection.getPageForParagraphIndex(result.paragraphIndex);
const auto nextParagraphPage = tempSection.getPageForParagraphIndex(result.paragraphIndex + 1);
if (paragraphPage.has_value()) {
int refinedPage = std::max(result.pageNumber, static_cast<int>(*paragraphPage));
if (nextParagraphPage.has_value()) {
const int lutSpan = static_cast<int>(*nextParagraphPage) - static_cast<int>(*paragraphPage);
// Only cap when the LUT span is >1. A span of 1 means the LUT granularity is too
// coarse to trust over the intra-spine position (e.g. a stale cache where the paragraph
// occupies different pages than at build time).
if (lutSpan > 1 && refinedPage >= static_cast<int>(*nextParagraphPage)) {
refinedPage = static_cast<int>(*nextParagraphPage) - 1;
}
}
char nextParaBuf[8];
if (nextParagraphPage.has_value())
snprintf(nextParaBuf, sizeof(nextParaBuf), "%d", *nextParagraphPage);
else
snprintf(nextParaBuf, sizeof(nextParaBuf), "none");
LOG_DBG("PM", "Paragraph %u -> LUT page %d, nextPara page %s, intra page %d, using %d", result.paragraphIndex,
*paragraphPage, nextParaBuf, result.pageNumber, refinedPage);
result.pageNumber = refinedPage;
} else {
LOG_DBG("PM", "Paragraph %u not found in section LUT", result.paragraphIndex);
}
}
}
return result;
}
std::string ProgressMapper::generateXPath(const std::shared_ptr<Epub>& epub, int spineIndex, float intra) {
const std::string base = "/body/DocFragment[" + std::to_string(spineIndex + 1) + "]/body";
if (intra <= 0.0f) return base;
size_t spineSize = 0;
const auto href = epub->getSpineItem(spineIndex).href;
if (href.empty() || !epub->getItemSize(href, &spineSize) || spineSize == 0) return base;
ParagraphStreamer s(static_cast<size_t>(spineSize * std::min(intra, 1.0f)));
if (!streamSpine(epub, spineIndex, s)) return base;
const int p = s.paragraphCount();
return (p > 0) ? base + "/p[" + std::to_string(p) + "]" : base;
}