gecko-dev/netwerk/base/nsMediaFragmentURIParser.cpp

375 строки
8.8 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsTArray.h"
#include "nsCharSeparatedTokenizer.h"
#include "nsEscape.h"
#include "nsIURI.h"
#include <utility>
#include "nsMediaFragmentURIParser.h"
using std::pair;
using std::make_pair;
namespace mozilla { namespace net {
nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsIURI* aURI)
: mClipUnit(eClipUnit_Pixel)
{
nsAutoCString ref;
aURI->GetRef(ref);
Parse(ref);
}
nsMediaFragmentURIParser::nsMediaFragmentURIParser(nsCString& aRef)
: mClipUnit(eClipUnit_Pixel)
{
Parse(aRef);
}
bool nsMediaFragmentURIParser::ParseNPT(nsDependentSubstring aString)
{
nsDependentSubstring original(aString);
if (aString.Length() > 4 &&
aString[0] == 'n' && aString[1] == 'p' &&
aString[2] == 't' && aString[3] == ':') {
aString.Rebind(aString, 4);
}
if (aString.Length() == 0) {
return false;
}
double start = -1.0;
double end = -1.0;
ParseNPTTime(aString, start);
if (aString.Length() == 0) {
mStart.emplace(start);
return true;
}
if (aString[0] != ',') {
aString.Rebind(original, 0);
return false;
}
aString.Rebind(aString, 1);
if (aString.Length() == 0) {
aString.Rebind(original, 0);
return false;
}
ParseNPTTime(aString, end);
if (end <= start || aString.Length() != 0) {
aString.Rebind(original, 0);
return false;
}
mStart.emplace(start);
mEnd.emplace(end);
return true;
}
bool nsMediaFragmentURIParser::ParseNPTTime(nsDependentSubstring& aString, double& aTime)
{
if (aString.Length() == 0) {
return false;
}
return
ParseNPTHHMMSS(aString, aTime) ||
ParseNPTMMSS(aString, aTime) ||
ParseNPTSec(aString, aTime);
}
// Return true if the given character is a numeric character
static bool IsDigit(nsDependentSubstring::char_type aChar)
{
return (aChar >= '0' && aChar <= '9');
}
// Return the index of the first character in the string that is not
// a numerical digit, starting from 'aStart'.
static uint32_t FirstNonDigit(nsDependentSubstring& aString, uint32_t aStart)
{
while (aStart < aString.Length() && IsDigit(aString[aStart])) {
++aStart;
}
return aStart;
}
bool nsMediaFragmentURIParser::ParseNPTSec(nsDependentSubstring& aString, double& aSec)
{
nsDependentSubstring original(aString);
if (aString.Length() == 0) {
return false;
}
uint32_t index = FirstNonDigit(aString, 0);
if (index == 0) {
return false;
}
nsDependentSubstring n(aString, 0, index);
nsresult ec;
int32_t s = PromiseFlatString(n).ToInteger(&ec);
if (NS_FAILED(ec)) {
return false;
}
aString.Rebind(aString, index);
double fraction = 0.0;
if (!ParseNPTFraction(aString, fraction)) {
aString.Rebind(original, 0);
return false;
}
aSec = s + fraction;
return true;
}
bool nsMediaFragmentURIParser::ParseNPTMMSS(nsDependentSubstring& aString, double& aTime)
{
nsDependentSubstring original(aString);
uint32_t mm = 0;
uint32_t ss = 0;
double fraction = 0.0;
if (!ParseNPTMM(aString, mm)) {
aString.Rebind(original, 0);
return false;
}
if (aString.Length() < 2 || aString[0] != ':') {
aString.Rebind(original, 0);
return false;
}
aString.Rebind(aString, 1);
if (!ParseNPTSS(aString, ss)) {
aString.Rebind(original, 0);
return false;
}
if (!ParseNPTFraction(aString, fraction)) {
aString.Rebind(original, 0);
return false;
}
aTime = mm * 60 + ss + fraction;
return true;
}
bool nsMediaFragmentURIParser::ParseNPTFraction(nsDependentSubstring& aString, double& aFraction)
{
double fraction = 0.0;
if (aString.Length() > 0 && aString[0] == '.') {
uint32_t index = FirstNonDigit(aString, 1);
if (index > 1) {
nsDependentSubstring number(aString, 0, index);
nsresult ec;
fraction = PromiseFlatString(number).ToDouble(&ec);
if (NS_FAILED(ec)) {
return false;
}
}
aString.Rebind(aString, index);
}
aFraction = fraction;
return true;
}
bool nsMediaFragmentURIParser::ParseNPTHHMMSS(nsDependentSubstring& aString, double& aTime)
{
nsDependentSubstring original(aString);
uint32_t hh = 0;
double seconds = 0.0;
if (!ParseNPTHH(aString, hh)) {
return false;
}
if (aString.Length() < 2 || aString[0] != ':') {
aString.Rebind(original, 0);
return false;
}
aString.Rebind(aString, 1);
if (!ParseNPTMMSS(aString, seconds)) {
aString.Rebind(original, 0);
return false;
}
aTime = hh * 3600 + seconds;
return true;
}
bool nsMediaFragmentURIParser::ParseNPTHH(nsDependentSubstring& aString, uint32_t& aHour)
{
if (aString.Length() == 0) {
return false;
}
uint32_t index = FirstNonDigit(aString, 0);
if (index == 0) {
return false;
}
nsDependentSubstring n(aString, 0, index);
nsresult ec;
int32_t u = PromiseFlatString(n).ToInteger(&ec);
if (NS_FAILED(ec)) {
return false;
}
aString.Rebind(aString, index);
aHour = u;
return true;
}
bool nsMediaFragmentURIParser::ParseNPTMM(nsDependentSubstring& aString, uint32_t& aMinute)
{
return ParseNPTSS(aString, aMinute);
}
bool nsMediaFragmentURIParser::ParseNPTSS(nsDependentSubstring& aString, uint32_t& aSecond)
{
if (aString.Length() < 2) {
return false;
}
if (IsDigit(aString[0]) && IsDigit(aString[1])) {
nsDependentSubstring n(aString, 0, 2);
nsresult ec;
int32_t u = PromiseFlatString(n).ToInteger(&ec);
if (NS_FAILED(ec)) {
return false;
}
aString.Rebind(aString, 2);
if (u >= 60)
return false;
aSecond = u;
return true;
}
return false;
}
static bool ParseInteger(nsDependentSubstring& aString,
int32_t& aResult)
{
uint32_t index = FirstNonDigit(aString, 0);
if (index == 0) {
return false;
}
nsDependentSubstring n(aString, 0, index);
nsresult ec;
int32_t s = PromiseFlatString(n).ToInteger(&ec);
if (NS_FAILED(ec)) {
return false;
}
aString.Rebind(aString, index);
aResult = s;
return true;
}
static bool ParseCommaSeparator(nsDependentSubstring& aString)
{
if (aString.Length() > 1 && aString[0] == ',') {
aString.Rebind(aString, 1);
return true;
}
return false;
}
bool nsMediaFragmentURIParser::ParseXYWH(nsDependentSubstring aString)
{
int32_t x, y, w, h;
ClipUnit clipUnit;
// Determine units.
if (StringBeginsWith(aString, NS_LITERAL_STRING("pixel:"))) {
clipUnit = eClipUnit_Pixel;
aString.Rebind(aString, 6);
} else if (StringBeginsWith(aString, NS_LITERAL_STRING("percent:"))) {
clipUnit = eClipUnit_Percent;
aString.Rebind(aString, 8);
} else {
clipUnit = eClipUnit_Pixel;
}
// Read and validate coordinates.
if (ParseInteger(aString, x) && x >= 0 &&
ParseCommaSeparator(aString) &&
ParseInteger(aString, y) && y >= 0 &&
ParseCommaSeparator(aString) &&
ParseInteger(aString, w) && w > 0 &&
ParseCommaSeparator(aString) &&
ParseInteger(aString, h) && h > 0 &&
aString.Length() == 0) {
// Reject invalid percentage coordinates.
if (clipUnit == eClipUnit_Percent &&
(x + w > 100 || y + h > 100)) {
return false;
}
mClip.emplace(x, y, w, h);
mClipUnit = clipUnit;
return true;
}
return false;
}
void nsMediaFragmentURIParser::Parse(nsACString& aRef)
{
// Create an array of possibly-invalid media fragments.
nsTArray< std::pair<nsCString, nsCString> > fragments;
nsCCharSeparatedTokenizer tokenizer(aRef, '&');
while (tokenizer.hasMoreTokens()) {
const nsCSubstring& nv = tokenizer.nextToken();
int32_t index = nv.FindChar('=');
if (index >= 0) {
nsAutoCString name;
nsAutoCString value;
NS_UnescapeURL(StringHead(nv, index), esc_Ref | esc_AlwaysCopy, name);
NS_UnescapeURL(Substring(nv, index + 1, nv.Length()),
esc_Ref | esc_AlwaysCopy, value);
fragments.AppendElement(make_pair(name, value));
}
}
// Parse the media fragment values.
bool gotTemporal = false, gotSpatial = false;
for (int i = fragments.Length() - 1 ; i >= 0 ; --i) {
if (gotTemporal && gotSpatial) {
// We've got one of each possible type. No need to look at the rest.
break;
} else if (!gotTemporal && fragments[i].first.EqualsLiteral("t")) {
nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
gotTemporal = ParseNPT(nsDependentSubstring(value, 0));
} else if (!gotSpatial && fragments[i].first.EqualsLiteral("xywh")) {
nsAutoString value = NS_ConvertUTF8toUTF16(fragments[i].second);
gotSpatial = ParseXYWH(nsDependentSubstring(value, 0));
}
}
}
} // namespace net
} // namespace mozilla