add refdict class, for holding a dictionary of reference-counted objects

-- experimental



git-svn-id: http://skia.googlecode.com/svn/trunk@730 2bbb7eff-a529-9590-31e7-b0007b416f81

5 files changed, 179 insertions, 0 deletions

diff --git a/include/core/SkRefDict.h b/include/core/SkRefDict.h
new file mode 100644
index 0000000000..c66f808b5d
--- /dev/null
+++ b/include/core/SkRefDict.h
@@ -0,0 +1,45 @@
+#ifndef SkRefDict_DEFINED
+#define SkRefDict_DEFINED
+
+#include "SkRefCnt.h"
+
+/**
+ *  A dictionary of string,refcnt pairs. The dictionary is also an owner of the
+ *  refcnt objects while they are contained.
+ */
+class SkRefDict : SkNoncopyable {
+public:
+    SkRefDict();
+    ~SkRefDict();
+
+    /**
+     *  Return the data associated with name[], or NULL if no matching entry
+     *  is found. The reference-count of the entry is not affected.
+     */
+    SkRefCnt* find(const char name[]) const;
+    
+    /**
+     *  If data is NULL, remove (if present) the entry matching name and call
+     *  prev_data->unref() on the data for the matching entry.
+     *  If data is not-NULL, replace the existing entry matching name and
+     *  call (prev_data->unref()), or add a new one. In either case,
+     *  data->ref() is called.
+     */
+    void set(const char name[], SkRefCnt* data);
+
+    /**
+     *  Remove the matching entry (if found) and unref its data.
+     */
+    void remove(const char name[]) { this->set(name, NULL); }
+
+    /**
+     *  Remove all entries, and unref() their associated data.
+     */
+    void removeAll();
+
+private:
+    struct Impl;
+    Impl* fImpl;
+};
+
+#endif
diff --git a/src/core/SkRefDict.cpp b/src/core/SkRefDict.cpp
new file mode 100644
index 0000000000..572ed7e180
--- /dev/null
+++ b/src/core/SkRefDict.cpp
@@ -0,0 +1,80 @@
+#include "SkRefDict.h"
+#include "SkString.h"
+
+struct SkRefDict::Impl {
+    Impl*       fNext;
+    SkString    fName;
+    SkRefCnt*   fData;
+};
+
+SkRefDict::SkRefDict() : fImpl(NULL) {}
+
+SkRefDict::~SkRefDict() {
+    this->removeAll();
+}
+
+SkRefCnt* SkRefDict::find(const char name[]) const {
+    if (NULL == name) {
+        return NULL;
+    }
+
+    Impl* rec = fImpl;
+    while (rec) {
+        if (rec->fName.equals(name)) {
+            return rec->fData;
+        }
+        rec = rec->fNext;
+    }
+    return NULL;
+}
+
+void SkRefDict::set(const char name[], SkRefCnt* data) {
+    if (NULL == name) {
+        return;
+    }
+
+    Impl* rec = fImpl;
+    Impl* prev = NULL;
+    while (rec) {
+        if (rec->fName.equals(name)) {
+            if (data) {
+                // replace
+                data->ref();
+                rec->fData->unref();
+                rec->fData = data;
+            } else {
+                // remove
+                rec->fData->unref();
+                if (prev) {
+                    prev->fNext = rec->fNext;
+                } else {
+                    fImpl = rec->fNext;
+                }
+            }
+            return;
+        }
+        prev = rec;
+        rec = rec->fNext;
+    }
+
+    // if get here, name was not found, so add it
+    data->ref();
+    rec = new Impl;
+    rec->fName.set(name);
+    rec->fData = data;
+    // prepend to the head of our list
+    rec->fNext = fImpl;
+    fImpl = rec;
+}
+
+void SkRefDict::removeAll() {
+    Impl* rec = fImpl;
+    while (rec) {
+        Impl* next = rec->fNext;
+        rec->fData->unref();
+        delete rec;
+        rec = next;
+    }
+    fImpl = NULL;
+}
+
diff --git a/src/core/core_files.mk b/src/core/core_files.mk
index 235fa76ac2..3e3436e9cc 100644
--- a/src/core/core_files.mk
+++ b/src/core/core_files.mk
@@ -71,6 +71,7 @@ SOURCE := \
     SkRasterizer.cpp \
     SkRect.cpp \
     SkRefCnt.cpp \
+    SkRefDict.cpp \
     SkRegion.cpp \
     SkRegion_rects.cpp \
     SkRegion_path.cpp \
diff --git a/tests/RefDictTest.cpp b/tests/RefDictTest.cpp
new file mode 100644
index 0000000000..61f64e9a2c
--- /dev/null
+++ b/tests/RefDictTest.cpp
@@ -0,0 +1,52 @@
+#include "Test.h"
+#include "SkRefDict.h"
+
+class TestRC : public SkRefCnt {
+};
+
+static void TestRefDict(skiatest::Reporter* reporter) {
+    TestRC    data0, data1;
+    SkRefDict dict;
+
+    REPORTER_ASSERT(reporter, NULL == dict.find(NULL));
+    REPORTER_ASSERT(reporter, NULL == dict.find("foo"));
+    REPORTER_ASSERT(reporter, NULL == dict.find("bar"));
+
+    dict.set("foo", &data0);
+    REPORTER_ASSERT(reporter, &data0 == dict.find("foo"));
+    REPORTER_ASSERT(reporter, 2 == data0.getRefCnt());
+
+    dict.set("foo", &data0);
+    REPORTER_ASSERT(reporter, &data0 == dict.find("foo"));
+    REPORTER_ASSERT(reporter, 2 == data0.getRefCnt());
+
+    dict.set("foo", &data1);
+    REPORTER_ASSERT(reporter, &data1 == dict.find("foo"));
+    REPORTER_ASSERT(reporter, 1 == data0.getRefCnt());
+    REPORTER_ASSERT(reporter, 2 == data1.getRefCnt());
+
+    dict.set("foo", NULL);
+    REPORTER_ASSERT(reporter, NULL == dict.find("foo"));
+    REPORTER_ASSERT(reporter, 1 == data0.getRefCnt());
+    REPORTER_ASSERT(reporter, 1 == data1.getRefCnt());
+
+    dict.set("foo", &data0);
+    dict.set("bar", &data1);
+    REPORTER_ASSERT(reporter, &data0 == dict.find("foo"));
+    REPORTER_ASSERT(reporter, &data1 == dict.find("bar"));
+    REPORTER_ASSERT(reporter, 2 == data0.getRefCnt());
+    REPORTER_ASSERT(reporter, 2 == data1.getRefCnt());
+
+    dict.set("foo", &data1);
+    REPORTER_ASSERT(reporter, &data1 == dict.find("foo"));
+    REPORTER_ASSERT(reporter, &data1 == dict.find("bar"));
+    REPORTER_ASSERT(reporter, 1 == data0.getRefCnt());
+    REPORTER_ASSERT(reporter, 3 == data1.getRefCnt());
+
+    dict.removeAll();
+    REPORTER_ASSERT(reporter, NULL == dict.find("foo"));
+    REPORTER_ASSERT(reporter, NULL == dict.find("bar"));
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("RefDict", RefDictTestClass, TestRefDict)
diff --git a/tests/tests_files.mk b/tests/tests_files.mk
index 0911c3f009..cc21c7c6f7 100644
--- a/tests/tests_files.mk
+++ b/tests/tests_files.mk
@@ -13,6 +13,7 @@ SOURCE := \
     ParsePathTest.cpp \
     PathMeasureTest.cpp \
     PathTest.cpp \
+    RefDictTest.cpp \
     RegionTest.cpp \
     Sk64Test.cpp \
     skia_test.cpp \