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Add support for NumberTree

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This commit is contained in:
Jonas Jenwald 2015-12-25 17:35:21 +01:00
parent 1eea0db897
commit 8ad18959d7
1 changed files with 61 additions and 39 deletions
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100
src/core/obj.js
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@ -48,6 +48,7 @@ var stringToPDFString = sharedUtil.stringToPDFString;
var stringToUTF8String = sharedUtil.stringToUTF8String; var stringToUTF8String = sharedUtil.stringToUTF8String;
var warn = sharedUtil.warn; var warn = sharedUtil.warn;
var isValidUrl = sharedUtil.isValidUrl; var isValidUrl = sharedUtil.isValidUrl;
var Util = sharedUtil.Util;
var Ref = corePrimitives.Ref; var Ref = corePrimitives.Ref;
var RefSet = corePrimitives.RefSet; var RefSet = corePrimitives.RefSet;
var RefSetCache = corePrimitives.RefSetCache; var RefSetCache = corePrimitives.RefSetCache;
@ -1137,24 +1138,23 @@ var XRef = (function XRefClosure() {
})(); })();
/** /**
* A NameTree is like a Dict but has some advantageous properties, see the * A NameTree/NumberTree is like a Dict but has some advantageous properties,
* spec (7.9.6) for more details. * see the specification (7.9.6 and 7.9.7) for additional details.
* TODO: implement all the Dict functions and make this more efficent. * TODO: implement all the Dict functions and make this more efficient.
*/ */
var NameTree = (function NameTreeClosure() { var NameOrNumberTree = (function NameOrNumberTreeClosure() {
function NameTree(root, xref) { function NameOrNumberTree(root, xref) {
this.root = root; throw new Error('Cannot initialize NameOrNumberTree.');
this.xref = xref;
} }
NameTree.prototype = { NameOrNumberTree.prototype = {
getAll: function NameTree_getAll() { getAll: function NameOrNumberTree_getAll() {
var dict = {}; var dict = {};
if (!this.root) { if (!this.root) {
return dict; return dict;
} }
var xref = this.xref; var xref = this.xref;
// reading name tree // Reading Name/Number tree.
var processed = new RefSet(); var processed = new RefSet();
processed.put(this.root); processed.put(this.root);
var queue = [this.root]; var queue = [this.root];
@ -1168,45 +1168,43 @@ var NameTree = (function NameTreeClosure() {
var kids = obj.get('Kids'); var kids = obj.get('Kids');
for (i = 0, n = kids.length; i < n; i++) { for (i = 0, n = kids.length; i < n; i++) {
var kid = kids[i]; var kid = kids[i];
if (processed.has(kid)) { assert(!processed.has(kid),
error('invalid destinations'); 'Duplicate entry in "' + this._type + '" tree.');
}
queue.push(kid); queue.push(kid);
processed.put(kid); processed.put(kid);
} }
continue; continue;
} }
var names = obj.get('Names'); var entries = obj.get(this._type);
if (names) { if (isArray(entries)) {
for (i = 0, n = names.length; i < n; i += 2) { for (i = 0, n = entries.length; i < n; i += 2) {
dict[xref.fetchIfRef(names[i])] = xref.fetchIfRef(names[i + 1]); dict[xref.fetchIfRef(entries[i])] = xref.fetchIfRef(entries[i + 1]);
} }
} }
} }
return dict; return dict;
}, },
get: function NameTree_get(destinationId) { get: function NameOrNumberTree_get(key) {
if (!this.root) { if (!this.root) {
return null; return null;
} }
var xref = this.xref; var xref = this.xref;
var kidsOrNames = xref.fetchIfRef(this.root); var kidsOrEntries = xref.fetchIfRef(this.root);
var loopCount = 0; var loopCount = 0;
var MAX_NAMES_LEVELS = 10; var MAX_LEVELS = 10;
var l, r, m; var l, r, m;
// Perform a binary search to quickly find the entry that // Perform a binary search to quickly find the entry that
// contains the named destination we are looking for. // contains the key we are looking for.
while (kidsOrNames.has('Kids')) { while (kidsOrEntries.has('Kids')) {
loopCount++; if (++loopCount > MAX_LEVELS) {
if (loopCount > MAX_NAMES_LEVELS) { warn('Search depth limit reached for "' + this._type + '" tree.');
warn('Search depth limit for named destionations has been reached.');
return null; return null;
} }
var kids = kidsOrNames.get('Kids'); var kids = kidsOrEntries.get('Kids');
if (!isArray(kids)) { if (!isArray(kids)) {
return null; return null;
} }
@ -1218,12 +1216,12 @@ var NameTree = (function NameTreeClosure() {
var kid = xref.fetchIfRef(kids[m]); var kid = xref.fetchIfRef(kids[m]);
var limits = kid.get('Limits'); var limits = kid.get('Limits');
if (destinationId < xref.fetchIfRef(limits[0])) { if (key < xref.fetchIfRef(limits[0])) {
r = m - 1; r = m - 1;
} else if (destinationId > xref.fetchIfRef(limits[1])) { } else if (key > xref.fetchIfRef(limits[1])) {
l = m + 1; l = m + 1;
} else { } else {
kidsOrNames = xref.fetchIfRef(kids[m]); kidsOrEntries = xref.fetchIfRef(kids[m]);
break; break;
} }
} }
@ -1232,33 +1230,57 @@ var NameTree = (function NameTreeClosure() {
} }
} }
// If we get here, then we have found the right entry. Now // If we get here, then we have found the right entry. Now go through the
// go through the named destinations in the Named dictionary // entries in the dictionary until we find the key we're looking for.
// until we find the exact destination we're looking for. var entries = kidsOrEntries.get(this._type);
var names = kidsOrNames.get('Names'); if (isArray(entries)) {
if (isArray(names)) {
// Perform a binary search to reduce the lookup time. // Perform a binary search to reduce the lookup time.
l = 0; l = 0;
r = names.length - 2; r = entries.length - 2;
while (l <= r) { while (l <= r) {
// Check only even indices (0, 2, 4, ...) because the // Check only even indices (0, 2, 4, ...) because the
// odd indices contain the actual D array. // odd indices contain the actual data.
m = (l + r) & ~1; m = (l + r) & ~1;
if (destinationId < xref.fetchIfRef(names[m])) { var currentKey = xref.fetchIfRef(entries[m]);
if (key < currentKey) {
r = m - 2; r = m - 2;
} else if (destinationId > xref.fetchIfRef(names[m])) { } else if (key > currentKey) {
l = m + 2; l = m + 2;
} else { } else {
return xref.fetchIfRef(names[m + 1]); return xref.fetchIfRef(entries[m + 1]);
} }
} }
} }
return null; return null;
} }
}; };
return NameOrNumberTree;
})();
var NameTree = (function NameTreeClosure() {
function NameTree(root, xref) {
this.root = root;
this.xref = xref;
this._type = 'Names';
}
Util.inherit(NameTree, NameOrNumberTree, {});
return NameTree; return NameTree;
})(); })();
var NumberTree = (function NumberTreeClosure() {
function NumberTree(root, xref) {
this.root = root;
this.xref = xref;
this._type = 'Nums';
}
Util.inherit(NumberTree, NameOrNumberTree, {});
return NumberTree;
})();
/** /**
* "A PDF file can refer to the contents of another file by using a File * "A PDF file can refer to the contents of another file by using a File
* Specification (PDF 1.1)", see the spec (7.11) for more details. * Specification (PDF 1.1)", see the spec (7.11) for more details.