1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* This Source Code Form is subject to the terms of the Mozilla Public 3 * License, v. 2.0. If a copy of the MPL was not distributed with this 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 5 6 #ifndef mozilla_image_ImageURL_h 7 #define mozilla_image_ImageURL_h 8 9 #include "nsIURI.h" 10 #include "MainThreadUtils.h" 11 #include "nsNetUtil.h" 12 #include "mozilla/HashFunctions.h" 13 #include "nsHashKeys.h" 14 #include "nsProxyRelease.h" 15 16 namespace mozilla { 17 namespace image { 18 19 class ImageCacheKey; 20 21 /** ImageURL 22 * 23 * nsStandardURL is not threadsafe, so this class is created to hold only the 24 * necessary URL data required for image loading and decoding. 25 * 26 * Note: Although several APIs have the same or similar prototypes as those 27 * found in nsIURI/nsStandardURL, the class does not implement nsIURI. This is 28 * intentional; functionality is limited, and is only useful for imagelib code. 29 * By not implementing nsIURI, external code cannot unintentionally be given an 30 * nsIURI pointer with this limited class behind it; instead, conversion to a 31 * fully implemented nsIURI is required (e.g. through NS_NewURI). 32 */ 33 class ImageURL { 34 public: ImageURL(nsIURI * aURI,nsresult & aRv)35 explicit ImageURL(nsIURI* aURI, nsresult& aRv) 36 : mURI(new nsMainThreadPtrHolder<nsIURI>("ImageURL::mURI", aURI)) { 37 MOZ_ASSERT(NS_IsMainThread(), "Cannot use nsIURI off main thread!"); 38 39 aRv = aURI->GetSpec(mSpec); 40 NS_ENSURE_SUCCESS_VOID(aRv); 41 42 aRv = aURI->GetScheme(mScheme); 43 NS_ENSURE_SUCCESS_VOID(aRv); 44 45 aRv = aURI->GetRef(mRef); 46 NS_ENSURE_SUCCESS_VOID(aRv); 47 } 48 NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ImageURL)49 NS_INLINE_DECL_THREADSAFE_REFCOUNTING(ImageURL) 50 51 nsresult GetSpec(nsACString& result) { 52 result = mSpec; 53 return NS_OK; 54 } 55 56 /// A weak pointer to the URI spec for this ImageURL. For logging only. Spec()57 const char* Spec() const { return mSpec.get(); } 58 59 enum TruncatedSpecStatus { FitsInto1k, TruncatedTo1k }; GetSpecTruncatedTo1k(nsACString & result)60 TruncatedSpecStatus GetSpecTruncatedTo1k(nsACString& result) { 61 static const size_t sMaxTruncatedLength = 1024; 62 63 if (sMaxTruncatedLength >= mSpec.Length()) { 64 result = mSpec; 65 return FitsInto1k; 66 } 67 68 result = Substring(mSpec, 0, sMaxTruncatedLength); 69 return TruncatedTo1k; 70 } 71 GetScheme(nsACString & result)72 nsresult GetScheme(nsACString& result) { 73 result = mScheme; 74 return NS_OK; 75 } 76 SchemeIs(const char * scheme,bool * result)77 nsresult SchemeIs(const char* scheme, bool* result) { 78 NS_PRECONDITION(scheme, "scheme is null"); 79 NS_PRECONDITION(result, "result is null"); 80 81 *result = mScheme.Equals(scheme); 82 return NS_OK; 83 } 84 GetRef(nsACString & result)85 nsresult GetRef(nsACString& result) { 86 result = mRef; 87 return NS_OK; 88 } 89 ToIURI()90 already_AddRefed<nsIURI> ToIURI() { 91 nsCOMPtr<nsIURI> newURI = mURI.get(); 92 return newURI.forget(); 93 } 94 95 bool operator==(const ImageURL& aOther) const { 96 // Note that we don't need to consider mScheme and mRef, because they're 97 // already represented in mSpec. 98 return mSpec == aOther.mSpec; 99 } 100 HasSameRef(const ImageURL & aOther)101 bool HasSameRef(const ImageURL& aOther) const { return mRef == aOther.mRef; } 102 103 private: 104 friend class ImageCacheKey; 105 ComputeHash(const Maybe<uint64_t> & aBlobSerial)106 PLDHashNumber ComputeHash(const Maybe<uint64_t>& aBlobSerial) const { 107 if (aBlobSerial) { 108 // For blob URIs, we hash the serial number of the underlying blob, so 109 // that different blob URIs which point to the same blob share a cache 110 // entry. We also include the ref portion of the URI to support media 111 // fragments which requires us to create different Image objects even if 112 // the source data is the same. 113 return HashGeneric(*aBlobSerial, HashString(mRef)); 114 } 115 // For non-blob URIs, we hash the URI spec. 116 return HashString(mSpec); 117 } 118 119 nsMainThreadPtrHandle<nsIURI> mURI; 120 121 // Since this is a basic storage class, no duplication of spec parsing is 122 // included in the functionality. Instead, the class depends upon the 123 // parsing implementation in the nsIURI class used in object construction. 124 // This means each field is stored separately, but since only a few are 125 // required, this small memory tradeoff for threadsafe usage should be ok. 126 nsAutoCString mSpec; 127 nsAutoCString mScheme; 128 nsAutoCString mRef; 129 ~ImageURL()130 ~ImageURL() {} 131 }; 132 133 } // namespace image 134 } // namespace mozilla 135 136 #endif // mozilla_image_ImageURL_h 137