зеркало из https://github.com/mozilla/pjs.git
146 строки
4.0 KiB
C++
146 строки
4.0 KiB
C++
// Test01.cpp
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#include "nsIDOMNode.h"
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#include "nsCOMPtr.h"
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#include "nsIPtr.h"
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NS_DEF_PTR(nsIDOMNode);
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/*
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This test file compares the generated code size of similar functions between raw
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COM interface pointers (|AddRef|ing and |Release|ing by hand), |nsCOMPtr|s, and
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the smart-pointer macro defined in "nsIPtr.h".
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Function size results were determined by examining dissassembly of the generated code.
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mXXX is the size of the generated code on the Macintosh. wXXX is the size on Windows.
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For these tests, all reasonable optimizations were enabled and exceptions were
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disabled (just as we build for release).
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The tests in this file explore only the simplest functionality: assigning a pointer
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to be reference counted into a [raw, nsCOMPtr, nsIPtr] object; ensuring that it is
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|AddRef|ed and |Release|d appropriately; calling through the pointer to a function
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supplied by the underlying COM interface.
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Windows:
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raw_optimized 31 bytes
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raw, nsCOMPtr* 34
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nsCOMPtr_optimized* 38
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nsCOMPtr_optimized 42
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nsCOMPtr 46
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nsIPtr, nsIPtr_optimized 34 + 196
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Macintosh:
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raw_optimized, nsCOMPtr_optimized 112 bytes (1.0000)
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nsCOMPtr 120 (1.0714) i.e., 7.14% bigger than raw_optimized et al
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nsIPtr_optimized 124 (1.1071)
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nsIPtr 136 (1.2143)
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raw 140 (1.2500)
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The overall difference in size between Windows and Macintosh is caused by the
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the PowerPC RISC architecture where every instruction is 4 bytes.
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Also note that on Windows, nsIPtr generates a out-of-line destructors
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which _are_ used, totalling an additional 196 bytes of code space per class used,
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per file it is used in.
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On Macintosh, both nsCOMPtr and nsIPtr generate out-of-line destructors which are
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not referenced, and which can be stripped by the linker.
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Also note that on all platforms, each use of the |NS_DEFINE_IID| macro adds 16 bytes of static
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data per file, while GetIID() has the same code profile and adds only 16 bytes of data to the entire
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program, reguardless of the number of uses (greater than one).
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*/
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void
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Test01_raw( nsIDOMNode* aDOMNode, nsString* aResult )
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// m140, w34
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{
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/*
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This test is designed to be more like a typical large function where,
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because you are working with several resources, you don't just return when
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one of them is |NULL|. Similarly: |Test01_nsCOMPtr00|, and |Test01_nsIPtr00|.
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*/
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nsIDOMNode* node = aDOMNode;
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NS_IF_ADDREF(node);
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if ( node )
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node->GetNodeName(*aResult);
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NS_IF_RELEASE(node);
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}
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void
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Test01_raw_optimized( nsIDOMNode* aDOMNode, nsString* aResult )
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// m112, w31
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{
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/*
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This test simulates smaller functions where you _do_ just return
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|NULL| at the first sign of trouble. Similarly: |Test01_nsCOMPtr01|,
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and |Test01_nsIPtr01|.
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*/
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/*
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This test produces smaller code that |Test01_raw| because it avoids
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the three tests: |NS_IF_...|, and |if ( node )|.
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*/
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// -- the following code is assumed, but is commented out so we compare only
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// the relevent generated code
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// if ( !aDOMNode )
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// return;
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nsIDOMNode* node = aDOMNode;
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NS_ADDREF(node);
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node->GetNodeName(*aResult);
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NS_RELEASE(node);
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}
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void
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Test01_nsCOMPtr( nsIDOMNode* aDOMNode, nsString* aResult )
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// m120, w46/34
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{
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nsCOMPtr<nsIDOMNode> node = aDOMNode;
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if ( node )
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node->GetNodeName(*aResult);
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}
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void
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Test01_nsCOMPtr_optimized( nsIDOMNode* aDOMNode, nsString* aResult )
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// m112, w42/38
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{
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// if ( !aDOMNode )
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// return;
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nsCOMPtr<nsIDOMNode> node = aDOMNode;
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node->GetNodeName(*aResult);
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}
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void
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Test01_nsIPtr( nsIDOMNode* aDOMNode, nsString* aResult )
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// m136, w34
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{
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nsIDOMNodePtr node = aDOMNode;
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node.AddRef();
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if ( node.IsNotNull() )
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node->GetNodeName(*aResult);
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}
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void
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Test01_nsIPtr_optimized( nsIDOMNode* aDOMNode, nsString* aResult )
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// m124, w34
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{
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// if ( !aDOMNode )
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// return;
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nsIDOMNodePtr node = aDOMNode;
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node.AddRef();
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node->GetNodeName(*aResult);
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}
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