From 951317fbfb58871a37d63cee6de1498bcfb63e6a Mon Sep 17 00:00:00 2001 From: Christopher Tate Date: Fri, 16 Nov 2012 15:58:08 -0800 Subject: [PATCH] Cache resource ID lookups in aapt This speeds up certain workloads considerably, particularly those involved in buildling apps via the SDK. Windows-based use should particularly benefit from the change. (cherry picked from commit d8dde13a63565dcd72bcf03a5088407b737ba793) Change-Id: I33835bc64ade77688d41e8bfcd371b0a5f59d8fd --- Android.mk | 1 + ResourceIdCache.cpp | 107 ++++++++++++++++++++++++++++++++++++++++++++ ResourceIdCache.h | 30 +++++++++++++ ResourceTable.cpp | 15 ++++--- 4 files changed, 148 insertions(+), 5 deletions(-) create mode 100644 ResourceIdCache.cpp create mode 100644 ResourceIdCache.h diff --git a/Android.mk b/Android.mk index d9b0681..5b88669 100644 --- a/Android.mk +++ b/Android.mk @@ -20,6 +20,7 @@ LOCAL_SRC_FILES := \ StringPool.cpp \ XMLNode.cpp \ ResourceFilter.cpp \ + ResourceIdCache.cpp \ ResourceTable.cpp \ Images.cpp \ Resource.cpp \ diff --git a/ResourceIdCache.cpp b/ResourceIdCache.cpp new file mode 100644 index 0000000..e03f4f6 --- /dev/null +++ b/ResourceIdCache.cpp @@ -0,0 +1,107 @@ +// +// Copyright 2012 The Android Open Source Project +// +// Manage a resource ID cache. + +#define LOG_TAG "ResourceIdCache" + +#include +#include +#include "ResourceIdCache.h" +#include +using namespace std; + + +static size_t mHits = 0; +static size_t mMisses = 0; +static size_t mCollisions = 0; + +static const size_t MAX_CACHE_ENTRIES = 2048; +static const android::String16 TRUE16("1"); +static const android::String16 FALSE16("0"); + +struct CacheEntry { + // concatenation of the relevant strings into a single instance + android::String16 hashedName; + uint32_t id; + + CacheEntry() {} + CacheEntry(const android::String16& name, uint32_t resId) : hashedName(name), id(resId) { } +}; + +static map< uint32_t, CacheEntry > mIdMap; + + +// djb2; reasonable choice for strings when collisions aren't particularly important +static inline uint32_t hashround(uint32_t hash, int c) { + return ((hash << 5) + hash) + c; /* hash * 33 + c */ +} + +static uint32_t hash(const android::String16& hashableString) { + uint32_t hash = 5381; + const char16_t* str = hashableString.string(); + while (int c = *str++) hash = hashround(hash, c); + return hash; +} + +namespace android { + +static inline String16 makeHashableName(const android::String16& package, + const android::String16& type, + const android::String16& name, + bool onlyPublic) { + String16 hashable = String16(name); + hashable += type; + hashable += package; + hashable += (onlyPublic ? TRUE16 : FALSE16); + return hashable; +} + +uint32_t ResourceIdCache::lookup(const android::String16& package, + const android::String16& type, + const android::String16& name, + bool onlyPublic) { + const String16 hashedName = makeHashableName(package, type, name, onlyPublic); + const uint32_t hashcode = hash(hashedName); + map::iterator item = mIdMap.find(hashcode); + if (item == mIdMap.end()) { + // cache miss + mMisses++; + return 0; + } + + // legit match? + if (hashedName == (*item).second.hashedName) { + mHits++; + return (*item).second.id; + } + + // collision + mCollisions++; + mIdMap.erase(hashcode); + return 0; +} + +// returns the resource ID being stored, for callsite convenience +uint32_t ResourceIdCache::store(const android::String16& package, + const android::String16& type, + const android::String16& name, + bool onlyPublic, + uint32_t resId) { + if (mIdMap.size() < MAX_CACHE_ENTRIES) { + const String16 hashedName = makeHashableName(package, type, name, onlyPublic); + const uint32_t hashcode = hash(hashedName); + mIdMap[hashcode] = CacheEntry(hashedName, resId); + } + return resId; +} + +void ResourceIdCache::dump() { + printf("ResourceIdCache dump:\n"); + printf("Size: %ld\n", mIdMap.size()); + printf("Hits: %ld\n", mHits); + printf("Misses: %ld\n", mMisses); + printf("(Collisions: %ld)\n", mCollisions); +} + +} diff --git a/ResourceIdCache.h b/ResourceIdCache.h new file mode 100644 index 0000000..65f7781 --- /dev/null +++ b/ResourceIdCache.h @@ -0,0 +1,30 @@ +// +// Copyright 2012 The Android Open Source Project +// +// Manage a resource ID cache. + +#ifndef RESOURCE_ID_CACHE_H +#define RESOURCE_ID_CACHE_H + +namespace android { +class android::String16; + +class ResourceIdCache { +public: + static uint32_t lookup(const android::String16& package, + const android::String16& type, + const android::String16& name, + bool onlyPublic); + + static uint32_t store(const android::String16& package, + const android::String16& type, + const android::String16& name, + bool onlyPublic, + uint32_t resId); + + static void dump(void); +}; + +} + +#endif diff --git a/ResourceTable.cpp b/ResourceTable.cpp index 3d7b088..52ebaf0 100644 --- a/ResourceTable.cpp +++ b/ResourceTable.cpp @@ -8,6 +8,7 @@ #include "XMLNode.h" #include "ResourceFilter.h" +#include "ResourceIdCache.h" #include #include @@ -1998,6 +1999,9 @@ uint32_t ResourceTable::getResId(const String16& package, const String16& name, bool onlyPublic) const { + uint32_t id = ResourceIdCache::lookup(package, type, name, onlyPublic); + if (id != 0) return id; // cache hit + sp p = mPackages.valueFor(package); if (p == NULL) return 0; @@ -2016,11 +2020,10 @@ uint32_t ResourceTable::getResId(const String16& package, } if (Res_INTERNALID(rid)) { - return rid; + return ResourceIdCache::store(package, type, name, onlyPublic, rid); } - return Res_MAKEID(p->getAssignedId()-1, - Res_GETTYPE(rid), - Res_GETENTRY(rid)); + return ResourceIdCache::store(package, type, name, onlyPublic, + Res_MAKEID(p->getAssignedId()-1, Res_GETTYPE(rid), Res_GETENTRY(rid))); } sp t = p->getTypes().valueFor(type); @@ -2029,7 +2032,9 @@ uint32_t ResourceTable::getResId(const String16& package, if (c == NULL) return 0; int32_t ei = c->getEntryIndex(); if (ei < 0) return 0; - return getResId(p, t, ei); + + return ResourceIdCache::store(package, type, name, onlyPublic, + getResId(p, t, ei)); } uint32_t ResourceTable::getResId(const String16& ref, -- 2.45.2