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-rw-r--r--src/bitfield/8byte.c40
-rw-r--r--src/bitfield/8byte.h29
-rw-r--r--src/canutil/read.c12
-rw-r--r--src/canutil/read.h4
-rw-r--r--src/canutil/write.c14
-rw-r--r--src/canutil/write.h4
6 files changed, 53 insertions, 50 deletions
diff --git a/src/bitfield/8byte.c b/src/bitfield/8byte.c
index 0f249d93..77251996 100644
--- a/src/bitfield/8byte.c
+++ b/src/bitfield/8byte.c
@@ -4,11 +4,13 @@
#include <limits.h>
#include <string.h>
-uint64_t bitmask(const uint8_t numBits) {
- return (((uint64_t)0x1) << numBits) - 1;
+#define EIGHTBYTE_BIT (8 * sizeof(uint64_t))
+
+uint64_t bitmask(const uint8_t bit_count) {
+ return (((uint64_t)0x1) << bit_count) - 1;
}
-static uint16_t bitsToBytes(uint32_t bits) {
+static uint16_t bits_to_bytes(uint32_t bits) {
uint8_t byte_count = bits / CHAR_BIT;
if(bits % CHAR_BIT != 0) {
++byte_count;
@@ -16,21 +18,21 @@ static uint16_t bitsToBytes(uint32_t bits) {
return byte_count;
}
-uint64_t getBitField(uint64_t data, const uint16_t startBit,
- const uint16_t numBits, bool bigEndian) {
+uint64_t get_bit_field(uint64_t source, const uint16_t startBit,
+ const uint16_t bit_count, bool big_endian) {
uint8_t result[8] = {0};
- if(!bigEndian) {
- data = __builtin_bswap64(data);
+ if(!big_endian) {
+ source = __builtin_bswap64(source);
}
- copyBitsRightAligned((const uint8_t*)&data, sizeof(data), startBit, numBits,
- result, sizeof(result));
+ copyBitsRightAligned((const uint8_t*)&source, sizeof(source), startBit,
+ bit_count, result, sizeof(result));
uint64_t int_result = 0;
- if(!bigEndian) {
+ if(!big_endian) {
// we need to swap the byte order of the array to get it into a
// uint64_t, but it's been right aligned so we have to be more careful
- for(int i = 0; i < bitsToBytes(numBits); i++) {
- int_result |= result[bitsToBytes(numBits) - i - 1] << (CHAR_BIT * i);
+ for(int i = 0; i < bits_to_bytes(bit_count); i++) {
+ int_result |= result[bits_to_bytes(bit_count) - i - 1] << (CHAR_BIT * i);
}
} else {
int_result = *(uint64_t*)result;
@@ -42,15 +44,15 @@ uint64_t getBitField(uint64_t data, const uint16_t startBit,
* TODO it would be nice to have a warning if you call with this a value that
* won't fit in the number of bits you've specified it should use.
*/
-void setBitField(uint64_t* data, uint64_t value, const uint16_t startPos,
- const uint16_t numBits) {
- int shiftDistance = 64 - startPos - numBits;
+void set_bit_field(uint64_t* destination, uint64_t value, const uint16_t offset,
+ const uint16_t bit_count) {
+ int shiftDistance = EIGHTBYTE_BIT - offset - bit_count;
value <<= shiftDistance;
- *data &= ~(bitmask(numBits) << shiftDistance);
- *data |= value;
+ *destination &= ~(bitmask(bit_count) << shiftDistance);
+ *destination |= value;
}
-uint8_t nthByte(const uint64_t source, const uint16_t byteNum) {
- return (source >> (64 - ((byteNum + 1) * CHAR_BIT))) & 0xFF;
+uint8_t nth_byte(const uint64_t source, const uint16_t byte_index) {
+ return (source >> (EIGHTBYTE_BIT - ((byte_index + 1) * CHAR_BIT))) & 0xFF;
}
diff --git a/src/bitfield/8byte.h b/src/bitfield/8byte.h
index 13b6aff3..9cbf61a9 100644
--- a/src/bitfield/8byte.h
+++ b/src/bitfield/8byte.h
@@ -14,17 +14,17 @@ extern "C" {
// inefficient on 32-bit platforms. how much work is it to switch vi-firmware
// to using uint8_t*?
-/* Public: Reads a subset of bits from a byte array.
+/* Public: Reads a subset of bits into a uint64_t.
*
- * data - the bytes in question.
- * startPos - the starting index of the bit field (beginning from 0).
+ * source - the bytes in question.
+ * offset - the starting index of the bit field (beginning from 0).
* numBits - the width of the bit field to extract.
- * bigEndian - if the data passed in is little endian, set this to false and it
+ * big_endian - if the data passed in is little endian, set this to false and it
* will be flipped before grabbing the bit field.
*
* Bit fields are positioned according to big-endian bit layout, but inside the
* bit field, values are represented as little-endian. Therefore, to get the bit
- * field, we swap the overall byte order if bigEndian == false and
+ * field, we swap the overall byte order if big_endian == false and
* use the value we find in the field (assuming the embedded platform is little
* endian).
*
@@ -42,30 +42,31 @@ extern "C" {
*
* Examples
*
- * uint64_t value = getBitField(data, 2, 4);
+ * uint64_t value = get_bit_field(data, 2, 4);
*
* Returns the value of the requested bit field.
*/
-uint64_t getBitField(uint64_t data, const uint16_t startPos,
- const uint16_t numBits, bool bigEndian);
+uint64_t get_bit_field(uint64_t source, const uint16_t offset,
+ const uint16_t bit_count, bool big_endian);
/* Public: Set the bit field in the given data array to the new value.
*
- * data - a byte array with size at least startPos + numBits.
+ * destination - a byte array with size at least offset + bit_count.
* value - the value to set in the bit field.
- * startPos - the starting index of the bit field (beginning from 0).
+ * offset - the starting index of the bit field (beginning from 0).
+ * bit_count - the number of bits to set in the data.
*/
-void setBitField(uint64_t* data, uint64_t value, const uint16_t startPos,
- const uint16_t numBits);
+void set_bit_field(uint64_t* destination, uint64_t value, const uint16_t offset,
+ const uint16_t bit_count);
/* Public: Retreive the nth byte out of 8 bytes in a uint64_t.
*
* source - the source data to retreive the byte from.
- * byteNum - the index of the byte, starting at 0 and assuming big-endian order.
+ * byte_index - the index of the byte, starting at 0 and assuming big-endian order.
*
* Returns the requested byte from the source bytes.
*/
-uint8_t nthByte(const uint64_t source, const uint16_t byteNum);
+uint8_t nth_byte(const uint64_t source, const uint16_t byte_index);
#ifdef __cplusplus
}
diff --git a/src/canutil/read.c b/src/canutil/read.c
index 6b4e40aa..5e882c3d 100644
--- a/src/canutil/read.c
+++ b/src/canutil/read.c
@@ -1,14 +1,14 @@
#include <bitfield/bitfield.h>
-float parseFloat(uint64_t data, uint8_t bitPosition, uint8_t bitSize,
+float bitfield_parse_float(uint64_t data, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset) {
- uint64_t rawValue = getBitField(data, bitPosition,
- bitSize, true);
- return rawValue * factor + offset;
+ uint64_t raw = get_bit_field(data, bit_offset,
+ bit_size, true);
+ return raw * factor + offset;
}
-bool parseBoolean(uint64_t data, uint8_t bitPosition, uint8_t bitSize,
+bool bitfield_parse_bool(uint64_t data, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset) {
- float value = parseFloat(data, bitPosition, bitSize, factor, offset);
+ float value = bitfield_parse_float(data, bit_offset, bit_size, factor, offset);
return value == 0.0 ? false : true;
}
diff --git a/src/canutil/read.h b/src/canutil/read.h
index 6ac4eebe..3742d6d1 100644
--- a/src/canutil/read.h
+++ b/src/canutil/read.h
@@ -16,10 +16,10 @@ extern "C" {
*
* Returns the final, transformed value of the signal.
*/
-float parseFloat(uint64_t data, uint8_t bitPosition, uint8_t bitSize,
+float bitfield_parse_float(uint64_t data, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset);
-bool parseBoolean(uint64_t data, uint8_t bitPosition, uint8_t bitSize,
+bool bitfield_parse_bool(uint64_t data, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset);
#ifdef __cplusplus
diff --git a/src/canutil/write.c b/src/canutil/write.c
index 64b57297..14d2a449 100644
--- a/src/canutil/write.c
+++ b/src/canutil/write.c
@@ -1,19 +1,19 @@
#include "write.h"
#include <bitfield/bitfield.h>
-uint64_t encodeFloat(float value, uint8_t bitPosition, uint8_t bitSize,
+uint64_t bitfield_encode_float(float value, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset) {
- float rawValue = (value - offset) / factor;
- if(rawValue > 0) {
+ float raw = (value - offset) / factor;
+ if(raw > 0) {
// round up to avoid losing precision when we cast to an int
- rawValue += 0.5;
+ raw += 0.5;
}
uint64_t result = 0;
- setBitField(&result, (uint64_t)rawValue, bitPosition, bitSize);
+ set_bit_field(&result, (uint64_t)raw, bit_offset, bit_size);
return result;
}
-uint64_t encodeBoolean(bool value, uint8_t bitPosition, uint8_t bitSize,
+uint64_t bitfield_encode_bool(bool value, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset) {
- return encodeFloat(value, offset, factor, bitPosition, bitSize);
+ return bitfield_encode_float(value, offset, factor, bit_offset, bit_size);
}
diff --git a/src/canutil/write.h b/src/canutil/write.h
index 1b086dbe..3d13b1df 100644
--- a/src/canutil/write.h
+++ b/src/canutil/write.h
@@ -8,10 +8,10 @@
extern "C" {
#endif
-uint64_t encodeFloat(float value, uint8_t bitPosition, uint8_t bitSize,
+uint64_t bitfield_encode_float(float value, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset);
-uint64_t encodeBoolean(bool value, uint8_t bitPosition, uint8_t bitSize,
+uint64_t bitfield_encode_bool(bool value, uint8_t bit_offset, uint8_t bit_size,
float factor, float offset);
#ifdef __cplusplus