Team2890/allwpilib
4
0
Fork 0
mirror of https://github.com/wpilibsuite/allwpilib synced 2026-06-23 01:21:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

I2C: Provide byte[] JNI interfaces.

Browse Source 
This avoids a direct byte buffer allocation on every read/write/transaction
on the byte[] variants.

Changes HAL I2C interfaces to use const for dataToSend.
This commit is contained in:
Peter Johnson
2017-11-15 21:41:58 -08:00
parent 6307d41002
commit 9021b37fd2
8 changed files with 161 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

117
wpilibj/src/main/java/edu/wpi/first/wpilibj/I2C.java
View File

@@ -72,20 +72,15 @@ public class I2C extends SensorBase {
*/
public synchronized boolean transaction(byte[] dataToSend, int sendSize,
byte[] dataReceived, int receiveSize) {
final int status;
ByteBuffer dataToSendBuffer = ByteBuffer.allocateDirect(sendSize);
if (sendSize > 0 && dataToSend != null) {
dataToSendBuffer.put(dataToSend);
if (dataToSend.length < sendSize) {
throw new IllegalArgumentException("dataToSend is too small, must be at least " + sendSize);
}
ByteBuffer dataReceivedBuffer = ByteBuffer.allocateDirect(receiveSize);
status = I2CJNI.i2CTransaction(m_port, (byte) m_deviceAddress, dataToSendBuffer,
(byte) sendSize, dataReceivedBuffer, (byte) receiveSize);
if (receiveSize > 0 && dataReceived != null) {
dataReceivedBuffer.get(dataReceived, 0, receiveSize);
if (dataReceived.length < receiveSize) {
throw new IllegalArgumentException(
"dataReceived is too small, must be at least " + receiveSize);
}
return status < 0;
return I2CJNI.i2CTransactionB(m_port, (byte) m_deviceAddress, dataToSend,
(byte) sendSize, dataReceived, (byte) receiveSize) < 0;
}
/**
@@ -94,16 +89,17 @@ public class I2C extends SensorBase {
* <p>This is a lower-level interface to the I2C hardware giving you more control over each
* transaction.
*
* @param dataToSend Buffer of data to send as part of the transaction. Must be allocated using
* ByteBuffer.allocateDirect().
* @param dataToSend Buffer of data to send as part of the transaction.
* @param sendSize Number of bytes to send as part of the transaction.
* @param dataReceived Buffer to read data into. Must be allocated using {@link
* ByteBuffer#allocateDirect(int)}.
* @param dataReceived Buffer to read data into.
* @param receiveSize Number of bytes to read from the device.
* @return Transfer Aborted... false for success, true for aborted.
*/
public synchronized boolean transaction(ByteBuffer dataToSend, int sendSize,
ByteBuffer dataReceived, int receiveSize) {
if (dataToSend.hasArray() && dataReceived.hasArray()) {
return transaction(dataToSend.array(), sendSize, dataReceived.array(), receiveSize);
}
if (!dataToSend.isDirect()) {
throw new IllegalArgumentException("dataToSend must be a direct buffer");
}
@@ -131,7 +127,7 @@ public class I2C extends SensorBase {
* @return Transfer Aborted... false for success, true for aborted.
*/
public boolean addressOnly() {
return transaction((byte[]) null, (byte) 0, null, (byte) 0);
return transaction(new byte[0], (byte) 0, new byte[0], (byte) 0);
}
/**
@@ -147,12 +143,8 @@ public class I2C extends SensorBase {
byte[] buffer = new byte[2];
buffer[0] = (byte) registerAddress;
buffer[1] = (byte) data;
ByteBuffer dataToSendBuffer = ByteBuffer.allocateDirect(2);
dataToSendBuffer.put(buffer);
return I2CJNI.i2CWrite(m_port, (byte) m_deviceAddress, dataToSendBuffer,
(byte) buffer.length) < 0;
return I2CJNI.i2CWriteB(m_port, (byte) m_deviceAddress, buffer,
(byte) buffer.length) < 0;
}
/**
@@ -164,11 +156,7 @@ public class I2C extends SensorBase {
* @return Transfer Aborted... false for success, true for aborted.
*/
public synchronized boolean writeBulk(byte[] data) {
ByteBuffer dataToSendBuffer = ByteBuffer.allocateDirect(data.length);
dataToSendBuffer.put(data);
return I2CJNI.i2CWrite(m_port, (byte) m_deviceAddress, dataToSendBuffer,
(byte) data.length) < 0;
return writeBulk(data, data.length);
}
/**
@@ -176,10 +164,31 @@ public class I2C extends SensorBase {
*
* <p>Write multiple bytes to a register on a device and wait until the transaction is complete.
*
* @param data The data to write to the device. Must be created using ByteBuffer.allocateDirect().
* @param data The data to write to the device.
* @param size The number of data bytes to write.
* @return Transfer Aborted... false for success, true for aborted.
*/
public synchronized boolean writeBulk(byte[] data, int size) {
if (data.length < size) {
throw new IllegalArgumentException(
"buffer is too small, must be at least " + size);
}
return I2CJNI.i2CWriteB(m_port, (byte) m_deviceAddress, data, (byte) size) < 0;
}
/**
* Execute a write transaction with the device.
*
* <p>Write multiple bytes to a register on a device and wait until the transaction is complete.
*
* @param data The data to write to the device.
* @param size The number of data bytes to write.
* @return Transfer Aborted... false for success, true for aborted.
*/
public synchronized boolean writeBulk(ByteBuffer data, int size) {
if (data.hasArray()) {
return writeBulk(data.array(), size);
}
if (!data.isDirect()) {
throw new IllegalArgumentException("must be a direct buffer");
}
@@ -208,6 +217,9 @@ public class I2C extends SensorBase {
if (count < 1) {
throw new BoundaryException("Value must be at least 1, " + count + " given");
}
if (buffer.length < count) {
throw new IllegalArgumentException("buffer is too small, must be at least " + count);
}
byte[] registerAddressArray = new byte[1];
registerAddressArray[0] = (byte) registerAddress;
@@ -215,6 +227,8 @@ public class I2C extends SensorBase {
return transaction(registerAddressArray, registerAddressArray.length, buffer, count);
}
private ByteBuffer m_readDataToSendBuffer = null;
/**
* Execute a read transaction with the device.
*
@@ -223,8 +237,7 @@ public class I2C extends SensorBase {
*
* @param registerAddress The register to read first in the transaction.
* @param count The number of bytes to read in the transaction.
* @param buffer A buffer to store the data read from the device. Must be created using
* ByteBuffer.allocateDirect().
* @param buffer A buffer to store the data read from the device.
* @return Transfer Aborted... false for success, true for aborted.
*/
public boolean read(int registerAddress, int count, ByteBuffer buffer) {
@@ -232,6 +245,10 @@ public class I2C extends SensorBase {
throw new BoundaryException("Value must be at least 1, " + count + " given");
}
if (buffer.hasArray()) {
return read(registerAddress, count, buffer.array());
}
if (!buffer.isDirect()) {
throw new IllegalArgumentException("must be a direct buffer");
}
@@ -239,10 +256,14 @@ public class I2C extends SensorBase {
throw new IllegalArgumentException("buffer is too small, must be at least " + count);
}
ByteBuffer dataToSendBuffer = ByteBuffer.allocateDirect(1);
dataToSendBuffer.put(0, (byte) registerAddress);
synchronized (this) {
if (m_readDataToSendBuffer == null) {
m_readDataToSendBuffer = ByteBuffer.allocateDirect(1);
}
m_readDataToSendBuffer.put(0, (byte) registerAddress);
return transaction(dataToSendBuffer, 1, buffer, count);
return transaction(m_readDataToSendBuffer, 1, buffer, count);
}
}
/**
@@ -259,13 +280,12 @@ public class I2C extends SensorBase {
if (count < 1) {
throw new BoundaryException("Value must be at least 1, " + count + " given");
}
if (buffer.length < count) {
throw new IllegalArgumentException("buffer is too small, must be at least " + count);
}
ByteBuffer dataReceivedBuffer = ByteBuffer.allocateDirect(count);
int retVal = I2CJNI.i2CRead(m_port, (byte) m_deviceAddress, dataReceivedBuffer,
(byte) count);
dataReceivedBuffer.get(buffer);
return retVal < 0;
return I2CJNI.i2CReadB(m_port, (byte) m_deviceAddress, buffer,
(byte) count) < 0;
}
/**
@@ -273,8 +293,7 @@ public class I2C extends SensorBase {
*
* <p>Read bytes from a device. This method does not write any data to prompt the device.
*
* @param buffer A pointer to the array of bytes to store the data read from the device. Must be
* created using ByteBuffer.allocateDirect().
* @param buffer A pointer to the array of bytes to store the data read from the device.
* @param count The number of bytes to read in the transaction.
* @return Transfer Aborted... false for success, true for aborted.
*/
@@ -284,6 +303,10 @@ public class I2C extends SensorBase {
+ " given");
}
if (buffer.hasArray()) {
return readOnly(buffer.array(), count);
}
if (!buffer.isDirect()) {
throw new IllegalArgumentException("must be a direct buffer");
}
@@ -322,21 +345,21 @@ public class I2C extends SensorBase {
public boolean verifySensor(int registerAddress, int count,
byte[] expected) {
// TODO: Make use of all 7 read bytes
ByteBuffer dataToSendBuffer = ByteBuffer.allocateDirect(1);
byte[] dataToSend = new byte[1];
ByteBuffer deviceData = ByteBuffer.allocateDirect(4);
byte[] deviceData = new byte[4];
for (int i = 0, curRegisterAddress = registerAddress;
i < count; i += 4, curRegisterAddress += 4) {
int toRead = count - i < 4 ? count - i : 4;
// Read the chunk of data. Return false if the sensor does not
// respond.
dataToSendBuffer.put(0, (byte) curRegisterAddress);
if (transaction(dataToSendBuffer, 1, deviceData, toRead)) {
dataToSend[0] = (byte) curRegisterAddress;
if (transaction(dataToSend, 1, deviceData, toRead)) {
return false;
}
for (byte j = 0; j < toRead; j++) {
if (deviceData.get(j) != expected[i + j]) {
if (deviceData[j] != expected[i + j]) {
return false;
}
}

8
wpilibj/src/main/java/edu/wpi/first/wpilibj/hal/I2CJNI.java
View File

@@ -16,10 +16,18 @@ public class I2CJNI extends JNIWrapper {
public static native int i2CTransaction(int port, byte address, ByteBuffer dataToSend,
byte sendSize, ByteBuffer dataReceived, byte receiveSize);
public static native int i2CTransactionB(int port, byte address, byte[] dataToSend,
byte sendSize, byte[] dataReceived, byte receiveSize);
public static native int i2CWrite(int port, byte address, ByteBuffer dataToSend, byte sendSize);
public static native int i2CWriteB(int port, byte address, byte[] dataToSend, byte sendSize);
public static native int i2CRead(int port, byte address, ByteBuffer dataReceived,
byte receiveSize);
public static native int i2CReadB(int port, byte address, byte[] dataReceived,
byte receiveSize);
public static native void i2CClose(int port);
}