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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /xpcom/io/nsSegmentedBuffer.cpp
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
Diffstat (limited to 'xpcom/io/nsSegmentedBuffer.cpp')
-rw-r--r--xpcom/io/nsSegmentedBuffer.cpp169
1 files changed, 169 insertions, 0 deletions
diff --git a/xpcom/io/nsSegmentedBuffer.cpp b/xpcom/io/nsSegmentedBuffer.cpp
new file mode 100644
index 000000000..ab42a73c7
--- /dev/null
+++ b/xpcom/io/nsSegmentedBuffer.cpp
@@ -0,0 +1,169 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "nsSegmentedBuffer.h"
+#include "nsMemory.h"
+
+nsresult
+nsSegmentedBuffer::Init(uint32_t aSegmentSize, uint32_t aMaxSize)
+{
+ if (mSegmentArrayCount != 0) {
+ return NS_ERROR_FAILURE; // initialized more than once
+ }
+ mSegmentSize = aSegmentSize;
+ mMaxSize = aMaxSize;
+#if 0 // testing...
+ mSegmentArrayCount = 2;
+#else
+ mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT;
+#endif
+ return NS_OK;
+}
+
+char*
+nsSegmentedBuffer::AppendNewSegment()
+{
+ if (GetSize() >= mMaxSize) {
+ return nullptr;
+ }
+
+ if (!mSegmentArray) {
+ uint32_t bytes = mSegmentArrayCount * sizeof(char*);
+ mSegmentArray = (char**)moz_xmalloc(bytes);
+ if (!mSegmentArray) {
+ return nullptr;
+ }
+ memset(mSegmentArray, 0, bytes);
+ }
+
+ if (IsFull()) {
+ uint32_t newArraySize = mSegmentArrayCount * 2;
+ uint32_t bytes = newArraySize * sizeof(char*);
+ char** newSegArray = (char**)moz_xrealloc(mSegmentArray, bytes);
+ if (!newSegArray) {
+ return nullptr;
+ }
+ mSegmentArray = newSegArray;
+ // copy wrapped content to new extension
+ if (mFirstSegmentIndex > mLastSegmentIndex) {
+ // deal with wrap around case
+ memcpy(&mSegmentArray[mSegmentArrayCount],
+ mSegmentArray,
+ mLastSegmentIndex * sizeof(char*));
+ memset(mSegmentArray, 0, mLastSegmentIndex * sizeof(char*));
+ mLastSegmentIndex += mSegmentArrayCount;
+ memset(&mSegmentArray[mLastSegmentIndex], 0,
+ (newArraySize - mLastSegmentIndex) * sizeof(char*));
+ } else {
+ memset(&mSegmentArray[mLastSegmentIndex], 0,
+ (newArraySize - mLastSegmentIndex) * sizeof(char*));
+ }
+ mSegmentArrayCount = newArraySize;
+ }
+
+ char* seg = (char*)malloc(mSegmentSize);
+ if (!seg) {
+ return nullptr;
+ }
+ mSegmentArray[mLastSegmentIndex] = seg;
+ mLastSegmentIndex = ModSegArraySize(mLastSegmentIndex + 1);
+ return seg;
+}
+
+bool
+nsSegmentedBuffer::DeleteFirstSegment()
+{
+ NS_ASSERTION(mSegmentArray[mFirstSegmentIndex] != nullptr, "deleting bad segment");
+ free(mSegmentArray[mFirstSegmentIndex]);
+ mSegmentArray[mFirstSegmentIndex] = nullptr;
+ int32_t last = ModSegArraySize(mLastSegmentIndex - 1);
+ if (mFirstSegmentIndex == last) {
+ mLastSegmentIndex = last;
+ return true;
+ } else {
+ mFirstSegmentIndex = ModSegArraySize(mFirstSegmentIndex + 1);
+ return false;
+ }
+}
+
+bool
+nsSegmentedBuffer::DeleteLastSegment()
+{
+ int32_t last = ModSegArraySize(mLastSegmentIndex - 1);
+ NS_ASSERTION(mSegmentArray[last] != nullptr, "deleting bad segment");
+ free(mSegmentArray[last]);
+ mSegmentArray[last] = nullptr;
+ mLastSegmentIndex = last;
+ return (bool)(mLastSegmentIndex == mFirstSegmentIndex);
+}
+
+bool
+nsSegmentedBuffer::ReallocLastSegment(size_t aNewSize)
+{
+ int32_t last = ModSegArraySize(mLastSegmentIndex - 1);
+ NS_ASSERTION(mSegmentArray[last] != nullptr, "realloc'ing bad segment");
+ char* newSegment = (char*)realloc(mSegmentArray[last], aNewSize);
+ if (newSegment) {
+ mSegmentArray[last] = newSegment;
+ return true;
+ }
+ return false;
+}
+
+void
+nsSegmentedBuffer::Empty()
+{
+ if (mSegmentArray) {
+ for (uint32_t i = 0; i < mSegmentArrayCount; i++) {
+ if (mSegmentArray[i]) {
+ free(mSegmentArray[i]);
+ }
+ }
+ free(mSegmentArray);
+ mSegmentArray = nullptr;
+ }
+ mSegmentArrayCount = NS_SEGMENTARRAY_INITIAL_COUNT;
+ mFirstSegmentIndex = mLastSegmentIndex = 0;
+}
+
+#if 0
+void
+TestSegmentedBuffer()
+{
+ nsSegmentedBuffer* buf = new nsSegmentedBuffer();
+ NS_ASSERTION(buf, "out of memory");
+ buf->Init(4, 16);
+ char* seg;
+ bool empty;
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(!empty, "DeleteFirstSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(!empty, "DeleteFirstSegment failed");
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ seg = buf->AppendNewSegment();
+ NS_ASSERTION(seg, "AppendNewSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(!empty, "DeleteFirstSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(!empty, "DeleteFirstSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(!empty, "DeleteFirstSegment failed");
+ empty = buf->DeleteFirstSegment();
+ NS_ASSERTION(empty, "DeleteFirstSegment failed");
+ delete buf;
+}
+#endif
+
+////////////////////////////////////////////////////////////////////////////////