replicant-frameworks_native/libs/binder/CursorWindow.cpp

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/*
* Copyright (C) 2006-2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#undef LOG_TAG
#define LOG_TAG "CursorWindow"
#include <utils/Log.h>
#include <binder/CursorWindow.h>
#include <cutils/ashmem.h>
#include <sys/mman.h>
#include <assert.h>
#include <string.h>
#include <stdlib.h>
namespace android {
CursorWindow::CursorWindow(const String8& name, int ashmemFd,
void* data, size_t size, bool readOnly) :
mName(name), mAshmemFd(ashmemFd), mData(data), mSize(size), mReadOnly(readOnly) {
mHeader = static_cast<Header*>(mData);
}
CursorWindow::~CursorWindow() {
::munmap(mData, mSize);
::close(mAshmemFd);
}
status_t CursorWindow::create(const String8& name, size_t size, CursorWindow** outCursorWindow) {
String8 ashmemName("CursorWindow: ");
ashmemName.append(name);
status_t result;
int ashmemFd = ashmem_create_region(ashmemName.string(), size);
if (ashmemFd < 0) {
result = -errno;
} else {
result = ashmem_set_prot_region(ashmemFd, PROT_READ | PROT_WRITE);
if (result >= 0) {
void* data = ::mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, ashmemFd, 0);
if (data == MAP_FAILED) {
result = -errno;
} else {
result = ashmem_set_prot_region(ashmemFd, PROT_READ);
if (result >= 0) {
CursorWindow* window = new CursorWindow(name, ashmemFd,
data, size, false /*readOnly*/);
result = window->clear();
if (!result) {
LOG_WINDOW("Created new CursorWindow: freeOffset=%d, "
"numRows=%d, numColumns=%d, mSize=%d, mData=%p",
window->mHeader->freeOffset,
window->mHeader->numRows,
window->mHeader->numColumns,
window->mSize, window->mData);
*outCursorWindow = window;
return OK;
}
delete window;
}
}
::munmap(data, size);
}
::close(ashmemFd);
}
*outCursorWindow = NULL;
return result;
}
status_t CursorWindow::createFromParcel(Parcel* parcel, CursorWindow** outCursorWindow) {
String8 name = parcel->readString8();
status_t result;
int ashmemFd = parcel->readFileDescriptor();
if (ashmemFd == int(BAD_TYPE)) {
result = BAD_TYPE;
} else {
ssize_t size = ashmem_get_size_region(ashmemFd);
if (size < 0) {
result = UNKNOWN_ERROR;
} else {
int dupAshmemFd = ::dup(ashmemFd);
if (dupAshmemFd < 0) {
result = -errno;
} else {
void* data = ::mmap(NULL, size, PROT_READ, MAP_SHARED, dupAshmemFd, 0);
if (data == MAP_FAILED) {
result = -errno;
} else {
CursorWindow* window = new CursorWindow(name, dupAshmemFd,
data, size, true /*readOnly*/);
LOG_WINDOW("Created CursorWindow from parcel: freeOffset=%d, "
"numRows=%d, numColumns=%d, mSize=%d, mData=%p",
window->mHeader->freeOffset,
window->mHeader->numRows,
window->mHeader->numColumns,
window->mSize, window->mData);
*outCursorWindow = window;
return OK;
}
::close(dupAshmemFd);
}
}
}
*outCursorWindow = NULL;
return result;
}
status_t CursorWindow::writeToParcel(Parcel* parcel) {
status_t status = parcel->writeString8(mName);
if (!status) {
status = parcel->writeDupFileDescriptor(mAshmemFd);
}
return status;
}
status_t CursorWindow::clear() {
if (mReadOnly) {
return INVALID_OPERATION;
}
mHeader->freeOffset = sizeof(Header) + sizeof(RowSlotChunk);
mHeader->firstChunkOffset = sizeof(Header);
mHeader->numRows = 0;
mHeader->numColumns = 0;
RowSlotChunk* firstChunk = static_cast<RowSlotChunk*>(offsetToPtr(mHeader->firstChunkOffset));
firstChunk->nextChunkOffset = 0;
return OK;
}
status_t CursorWindow::setNumColumns(uint32_t numColumns) {
if (mReadOnly) {
return INVALID_OPERATION;
}
uint32_t cur = mHeader->numColumns;
if ((cur > 0 || mHeader->numRows > 0) && cur != numColumns) {
LOGE("Trying to go from %d columns to %d", cur, numColumns);
return INVALID_OPERATION;
}
mHeader->numColumns = numColumns;
return OK;
}
status_t CursorWindow::allocRow() {
if (mReadOnly) {
return INVALID_OPERATION;
}
// Fill in the row slot
RowSlot* rowSlot = allocRowSlot();
if (rowSlot == NULL) {
return NO_MEMORY;
}
// Allocate the slots for the field directory
size_t fieldDirSize = mHeader->numColumns * sizeof(FieldSlot);
uint32_t fieldDirOffset = alloc(fieldDirSize, true /*aligned*/);
if (!fieldDirOffset) {
mHeader->numRows--;
LOG_WINDOW("The row failed, so back out the new row accounting "
"from allocRowSlot %d", mHeader->numRows);
return NO_MEMORY;
}
FieldSlot* fieldDir = static_cast<FieldSlot*>(offsetToPtr(fieldDirOffset));
memset(fieldDir, 0, fieldDirSize);
LOG_WINDOW("Allocated row %u, rowSlot is at offset %u, fieldDir is %d bytes at offset %u\n",
mHeader->numRows - 1, offsetFromPtr(rowSlot), fieldDirSize, fieldDirOffset);
rowSlot->offset = fieldDirOffset;
return OK;
}
status_t CursorWindow::freeLastRow() {
if (mReadOnly) {
return INVALID_OPERATION;
}
if (mHeader->numRows > 0) {
mHeader->numRows--;
}
return OK;
}
uint32_t CursorWindow::alloc(size_t size, bool aligned) {
uint32_t padding;
if (aligned) {
// 4 byte alignment
padding = (~mHeader->freeOffset + 1) & 3;
} else {
padding = 0;
}
uint32_t offset = mHeader->freeOffset + padding;
uint32_t nextFreeOffset = offset + size;
if (nextFreeOffset > mSize) {
LOGW("Window is full: requested allocation %d bytes, "
"free space %d bytes, window size %d bytes",
size, freeSpace(), mSize);
return 0;
}
mHeader->freeOffset = nextFreeOffset;
return offset;
}
CursorWindow::RowSlot* CursorWindow::getRowSlot(uint32_t row) {
uint32_t chunkPos = row;
RowSlotChunk* chunk = static_cast<RowSlotChunk*>(
offsetToPtr(mHeader->firstChunkOffset));
while (chunkPos >= ROW_SLOT_CHUNK_NUM_ROWS) {
chunk = static_cast<RowSlotChunk*>(offsetToPtr(chunk->nextChunkOffset));
chunkPos -= ROW_SLOT_CHUNK_NUM_ROWS;
}
return &chunk->slots[chunkPos];
}
CursorWindow::RowSlot* CursorWindow::allocRowSlot() {
uint32_t chunkPos = mHeader->numRows;
RowSlotChunk* chunk = static_cast<RowSlotChunk*>(
offsetToPtr(mHeader->firstChunkOffset));
while (chunkPos > ROW_SLOT_CHUNK_NUM_ROWS) {
chunk = static_cast<RowSlotChunk*>(offsetToPtr(chunk->nextChunkOffset));
chunkPos -= ROW_SLOT_CHUNK_NUM_ROWS;
}
if (chunkPos == ROW_SLOT_CHUNK_NUM_ROWS) {
if (!chunk->nextChunkOffset) {
chunk->nextChunkOffset = alloc(sizeof(RowSlotChunk), true /*aligned*/);
if (!chunk->nextChunkOffset) {
return NULL;
}
}
chunk = static_cast<RowSlotChunk*>(offsetToPtr(chunk->nextChunkOffset));
chunk->nextChunkOffset = 0;
chunkPos = 0;
}
mHeader->numRows += 1;
return &chunk->slots[chunkPos];
}
CursorWindow::FieldSlot* CursorWindow::getFieldSlot(uint32_t row, uint32_t column) {
if (row >= mHeader->numRows || column >= mHeader->numColumns) {
LOGE("Failed to read row %d, column %d from a CursorWindow which "
"has %d rows, %d columns.",
row, column, mHeader->numRows, mHeader->numColumns);
return NULL;
}
RowSlot* rowSlot = getRowSlot(row);
if (!rowSlot) {
LOGE("Failed to find rowSlot for row %d.", row);
return NULL;
}
FieldSlot* fieldDir = static_cast<FieldSlot*>(offsetToPtr(rowSlot->offset));
return &fieldDir[column];
}
status_t CursorWindow::putBlob(uint32_t row, uint32_t column, const void* value, size_t size) {
return putBlobOrString(row, column, value, size, FIELD_TYPE_BLOB);
}
status_t CursorWindow::putString(uint32_t row, uint32_t column, const char* value,
size_t sizeIncludingNull) {
return putBlobOrString(row, column, value, sizeIncludingNull, FIELD_TYPE_STRING);
}
status_t CursorWindow::putBlobOrString(uint32_t row, uint32_t column,
const void* value, size_t size, int32_t type) {
if (mReadOnly) {
return INVALID_OPERATION;
}
FieldSlot* fieldSlot = getFieldSlot(row, column);
if (!fieldSlot) {
return BAD_VALUE;
}
uint32_t offset = alloc(size);
if (!offset) {
return NO_MEMORY;
}
memcpy(offsetToPtr(offset), value, size);
fieldSlot->type = type;
fieldSlot->data.buffer.offset = offset;
fieldSlot->data.buffer.size = size;
return OK;
}
status_t CursorWindow::putLong(uint32_t row, uint32_t column, int64_t value) {
if (mReadOnly) {
return INVALID_OPERATION;
}
FieldSlot* fieldSlot = getFieldSlot(row, column);
if (!fieldSlot) {
return BAD_VALUE;
}
fieldSlot->type = FIELD_TYPE_INTEGER;
fieldSlot->data.l = value;
return OK;
}
status_t CursorWindow::putDouble(uint32_t row, uint32_t column, double value) {
if (mReadOnly) {
return INVALID_OPERATION;
}
FieldSlot* fieldSlot = getFieldSlot(row, column);
if (!fieldSlot) {
return BAD_VALUE;
}
fieldSlot->type = FIELD_TYPE_FLOAT;
fieldSlot->data.d = value;
return OK;
}
status_t CursorWindow::putNull(uint32_t row, uint32_t column) {
if (mReadOnly) {
return INVALID_OPERATION;
}
FieldSlot* fieldSlot = getFieldSlot(row, column);
if (!fieldSlot) {
return BAD_VALUE;
}
fieldSlot->type = FIELD_TYPE_NULL;
fieldSlot->data.buffer.offset = 0;
fieldSlot->data.buffer.size = 0;
return OK;
}
}; // namespace android