From 3fa7ab9a170b40b6f5d6144cff9093a01c868946 Mon Sep 17 00:00:00 2001
From: Nick Dimiduk
+ * Each value is encoded as one or more bytes. The first byte of the encoding,
+ * its meaning, and a terse description of the bytes that follow is given by
+ * the following table:
+ * Numeric instance over a double.
+ */
+ public Numeric(double val) {
+ isR = true;
+ r = val;
+ isZ = false;
+ z = 0;
+ bd = null;
+ }
+
+ /**
+ * Create an Numeric instance over a long.
+ */
+ public Numeric(long val) {
+ isZ = true;
+ z = val;
+ isR = false;
+ r = 0.0;
+ bd = null;
+ }
+
+ /**
+ * Create an Numeric instance over a BigDecimal .
+ */
+ public Numeric(BigDecimal val) {
+ if (null == val) throw new NullPointerException();
+
+ // see if this can be a long instead
+ boolean isLong = false;
+ long lng = 0;
+ try {
+ lng = val.longValueExact();
+ isLong = true;
+ } catch (ArithmeticException e) {
+ }
+
+ if (isLong) {
+ isZ = true;
+ z = lng;
+ isR = false;
+ r = 0.0;
+ bd = null;
+ } else {
+ // doesn't fit in a long, fall back to BD
+ bd = val.round(MATH_CONTEXT);
+ isZ = false;
+ isR = false;
+ z = 0;
+ r = 0.0;
+ }
+ }
+
+ /**
+ * Returns true if the Number is an Integer and
+ * fits in a long, false otherwise.
+ */
+ public boolean isInteger() {
+ return isZ;
+ }
+
+ /**
+ * Returns true if the Number is a Real and fits
+ * in a double, false otherwise.
+ */
+ public boolean isReal() {
+ return isR;
+ }
+
+ /**
+ * Returns true if the Number is infinitely large
+ * in magnitude, false otherwise.
+ */
+ public boolean isInfinite() {
+ return isR && Double.isInfinite(r);
+ }
+
+ /**
+ * Returns true if the Number is a Not-a-Number
+ * (NaN) value, false otherwise.
+ */
+ public boolean isNaN() {
+ return isR && Double.isNaN(r);
+ }
+
+ /**
+ * Retrieve the value as a BigDecimal. This will silently
+ * promote a double or long to a
+ * BigDecimal when possible, so use it only if a primitive
+ * value is not available. Check availability using {@link #isInteger()} and
+ * {@link #isReal()}.
+ * @throws NumberFormatException if the
+ * Number is infinite or NaN.
+ */
+ public BigDecimal exactValue() {
+ return null == bd ? isR ? BigDecimal.valueOf(r) : BigDecimal.valueOf(z) : bd;
+ }
+
+ @Override
+ public double doubleValue() {
+ return isReal() ? r : isInteger() ? (double) z : bd.doubleValue();
+ }
+
+ @Override
+ public int intValue() {
+ return isInteger() ? (int) z : isReal() ? (int) r : bd.intValue();
+ }
+
+ @Override
+ public long longValue() {
+ return isInteger() ? z : isReal() ? (long) r : bd.longValue();
+ }
+
+ @Override
+ public float floatValue() {
+ return isReal() ? (float) r : isInteger() ? (float) z : bd.floatValue();
+ }
+
+ @Override
+ public String toString() {
+ return isReal() ? Double.toString(r) : isInteger() ? Long.toString(z) : bd.toString();
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) return true;
+ if (null == o) return false;
+ if (!(o instanceof Numeric)) return false;
+ Numeric that = (Numeric) o;
+ if (this.isInteger() && that.isInteger()) return this.longValue() == that.longValue();
+ if (this.isReal() && that.isReal()) return this.doubleValue() == that.doubleValue();
+ return 0 == this.exactValue().compareTo(that.exactValue());
+ }
+
+ @Override
+ public int hashCode() {
+ if (0 != hashCode) return hashCode;
+ int result = 1;
+ if (isInteger()) {
+ result = result * 23 + (int) (z ^ (z >>> 32));
+ } else if (isReal()) {
+ long bits = Double.doubleToLongBits(r);
+ result = result * 13 + (int) (bits ^ (bits >>> 32));
+ } else {
+ result = result * 17 + bd.hashCode();
+ }
+ hashCode = result;
+ return result;
+ }
+}
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/util/Order.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/util/Order.java
new file mode 100644
index 0000000..1123528
--- /dev/null
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/util/Order.java
@@ -0,0 +1,76 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.hadoop.hbase.util;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
+/**
+ * Used to describe or modify the lexicographical sort order of a byte[].
+ * Default ordering is considered ASCENDING. The order of a byte[] can be
+ * inverted, resulting in DESCENDING order, by replacing each byte with its
+ * 1's compliment.
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public enum Order {
+ ASCENDING, DESCENDING;
+
+ private static final byte mask = (byte) 0xff;
+
+ /**
+ * Returns the adjusted trichotomous value according to the ordering imposed
+ * by this Order.
+ */
+ public int cmp(int cmp) {
+ return cmp * (this == ASCENDING ? 1 : -1);
+ }
+
+ /**
+ * Apply order to the byte val.
+ */
+ public byte apply(byte val) {
+ return (byte) (this == ASCENDING ? val : val ^ mask);
+ }
+
+ /**
+ * Apply order to the byte array val.
+ */
+ public void apply(byte[] val) {
+ if (this != DESCENDING) return;
+ for (int i = 0; i < val.length; i++) {
+ val[i] ^= mask;
+ }
+ }
+
+ /**
+ * Apply order to the byte array val according to the Order.
+ */
+ public void apply(byte[] val, int offset, int length) {
+ if (this != DESCENDING) return;
+ for (int i = 0; i < length; i++) {
+ val[offset + i] ^= mask;
+ }
+ }
+
+ @Override
+ public String toString() {
+ return this == ASCENDING ? "ASCENDING" : "DESCENDING";
+ }
+}
+
diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/util/OrderedBytes.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/util/OrderedBytes.java
new file mode 100644
index 0000000..9b82562
--- /dev/null
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/util/OrderedBytes.java
@@ -0,0 +1,1286 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.hadoop.hbase.util;
+
+import static org.apache.hadoop.hbase.util.Order.ASCENDING;
+import static org.apache.hadoop.hbase.util.Order.DESCENDING;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.nio.charset.Charset;
+import java.util.Arrays;
+import java.util.Comparator;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
+import com.google.common.annotations.VisibleForTesting;
+
+/**
+ * Utility class that handles ordered byte arrays. That is, unlike
+ * {@link Bytes}, these methods produce byte arrays which maintain the sort
+ * order of the original values.
+ * Encoding Format summary
+ *
+ *
+ *
+ * Content Type Encoding
+ * NULL 0x05
+ * negative infinity 0x07
+ * negative large 0x08, ~E, ~M
+ * negative medium 0x13-E, ~M
+ * negative small 0x14, -E, ~M
+ * zero 0x15
+ * positive small 0x16, ~-E, M
+ * positive medium 0x17+E, M
+ * positive large 0x22, E, M
+ * positive infinity 0x23
+ * NaN 0x25
+ * fixed-length 32-bit integer 0x27, I
+ * fixed-length 64-bit integer 0x28, I
+ * fixed-length 32-bit float 0x30, F
+ * fixed-length 64-bit float 0x31, F
+ * text 0x33, T
+ * variable binary 0x35, B
+ * copy binary 0x36, X
+ * Each value that is a NULL encodes as a single byte of 0x05. Since every + * other value encoding begins with a byte greater than 0x05, this forces NULL + * values to sort first. + *
+ *+ * Each text value begins with a single byte of 0x33 and ends with a single + * byte of 0x00. There are zero or more intervening bytes that encode the text + * value. The intervening bytes are chosen so that the encoding will sort in + * the desired collating order. The intervening bytes may not contain a 0x00 + * character; the only 0x00 byte allowed in a text encoding is the final byte. + *
+ *+ * The text encoding ends in 0x00 in order to ensure that when there are two + * strings where one is a prefix of the other that the shorter string will + * sort first. + *
+ *+ * There are two encoding strategies for binary fields, referred to as + * "BlobVar" and "BlobCopy". BlobVar is less efficient in both space and + * encoding time. It has no limitations on the range of encoded values. + * BlobCopy is a byte-for-byte copy of the input data followed by a + * termination byte. It is extremely fast to encode and decode. It carries the + * restriction of not allowing a 0x00 value in the input byte[] as this value + * is used as the termination byte. + *
+ *
+ * "BlobVar" encodes the input byte[] in a manner similar to a variable length
+ * integer encoding. As with the other OrderedBytes encodings,
+ * the first encoded byte is used to indicate what kind of value follows. This
+ * header byte is 0x35 for BlobVar encoded values. As with the traditional
+ * varint encoding, the most significant bit of each subsequent encoded
+ * byte is used as a continuation marker. The 7 remaining bits
+ * contain the 7 most significant bits of the first unencoded byte. The next
+ * encoded byte starts with a continuation marker in the MSB. The least
+ * significant bit from the first unencoded byte follows, and the remaining 6
+ * bits contain the 6 MSBs of the second unencoded byte. The encoding
+ * continues, encoding 7 bytes on to 8 encoded bytes. The MSB of the final
+ * encoded byte contains a termination marker rather than a continuation
+ * marker, and any remaining bits from the final input byte. Any trailing bits
+ * in the final encoded byte are zeros.
+ *
+ * "BlobCopy" is a simple byte-for-byte copy of the input data. It uses 0x36 + * as the header byte, and is terminated by 0x00. This alternative encoding is + * more efficient, but it cannot accept values containing a 0x00 byte. + *
+ *+ * Numeric values must be coded so as to sort in numeric order. We assume that + * numeric values can be both integer and floating point values. The wrapper + * class {@link Numeric} is used to smooth over values decoded using this + * scheme. + *
+ *+ * Simplest cases first: If the numeric value is a NaN, then the encoding is a + * single byte of 0x25. This causes NaN values to sort after to every other + * numeric value. + *
+ *+ * If the numeric value is a negative infinity then the encoding is a single + * byte of 0x07. Since every other numeric value except NaN has a larger + * initial byte, this encoding ensures that negative infinity will sort prior + * to every other numeric value other than NaN. + *
+ *+ * If the numeric value is a positive infinity then the encoding is a single + * byte of 0x23. Every other numeric value encoding begins with a smaller + * byte, ensuring that positive infinity always sorts last among numeric + * values. 0x23 is also smaller than 0x33, the initial byte of a text value, + * ensuring that every numeric value sorts before every text value. + *
+ *+ * If the numeric value is exactly zero then it is encoded as a single byte of + * 0x15. Finite negative values will have initial bytes of 0x08 through 0x14 + * and finite positive values will have initial bytes of 0x16 through 0x22. + *
+ *+ * For all numeric values, we compute a mantissa M and an exponent E. The + * mantissa is a base-100 representation of the value. The exponent E + * determines where to put the decimal point. + *
+ *+ * Each centimal digit of the mantissa is stored in a byte. If the value of + * the centimal digit is X (hence X≥0 and X≤99) then the byte value will + * be 2*X+1 for every byte of the mantissa, except for the last byte which + * will be 2*X+0. The mantissa must be the minimum number of bytes necessary + * to represent the value; trailing X==0 digits are omitted. This means that + * the mantissa will never contain a byte with the value 0x00. + *
+ *+ * If we assume all digits of the mantissa occur to the right of the decimal + * point, then the exponent E is the power of one hundred by which one must + * multiply the mantissa to recover the original value. + *
+ *+ * Values are classified as large, medium, or small according to the value of + * E. If E is 11 or more, the value is large. For E between 0 and 10, the + * value is medium. For E less than zero, the value is small. + *
+ *+ * Large positive values are encoded as a single byte 0x22 followed by E as a + * varint and then M. Medium positive values are a single byte of 0x17+E + * followed by M. Small positive values are encoded as a single byte 0x16 + * followed by the ones-complement of the varint for -E followed by M. + *
+ *+ * Small negative values are encoded as a single byte 0x14 followed by -E as a + * varint and then the ones-complement of M. Medium negative values are + * encoded as a byte 0x13-E followed by the ones-complement of M. Large + * negative values consist of the single byte 0x08 followed by the + * ones-complement of the varint encoding of E followed by the ones-complement + * of M. + *
+ *+ * All 4-byte integers are serialized to a 5-byte, fixed-width, sortable byte + * format. All 8-byte integers are serialized to the equivelant 9-byte format. + * Serialization is performed by writing a header byte, inverting the integer + * sign bit and writing the resulting bytes to the byte array in big endian + * order. + *
+ *+ * 32-bit and 64-bit floating point numbers are encoded to a 5-byte and 9-byte + * encoding format, respectively. The format is identical, save for the + * precision respected in each step of the operation. + *
+ * This format ensures the following total ordering of floating point values: + * Float.NEGATIVE_INFINITY < -Float.MAX_VALUE < ... < + * -Float.MIN_VALUE < -0.0 < +0.0; < Float.MIN_VALUE < ... < + * Float.MAX_VALUE < Float.POSITIVE_INFINITY < Float.NaN + *
+ *+ * Floating point numbers are encoded as specified in IEEE 754. A 32-bit + * single precision float consists of a sign bit, 8-bit unsigned exponent + * encoded in offset-127 notation, and a 23-bit significand. The format is + * described further in the Single Precision + * Floating Point Wikipedia page + *
+ *+ * The value of a normal float is -1 sign bit × + * 2exponent - 127 × 1.significand + *
+ *+ * The IEE754 floating point format already preserves sort ordering for + * positive floating point numbers when the raw bytes are compared in most + * significant byte order. This is discussed further at http://www.cygnus-software.com/papers/comparingfloats/comparingfloats. + * htm + *
+ *+ * Thus, we need only ensure that negative numbers sort in the the exact + * opposite order as positive numbers (so that say, negative infinity is less + * than negative 1), and that all negative numbers compare less than any + * positive number. To accomplish this, we invert the sign bit of all floating + * point numbers, and we also invert the exponent and significand bits if the + * floating point number was negative. + *
+ *
+ * More specifically, we first store the floating point bits into a 32-bit int
+ * j using {@link Float#floatToIntBits}. This method collapses
+ * all NaNs into a single, canonical NaN value but otherwise leaves the bits
+ * unchanged. We then compute
+ *
+ * j ˆ= (j >> (Integer.SIZE - 1)) | Integer.MIN_SIZE + *+ *
+ * which inverts the sign bit and XOR's all other bits with the sign bit
+ * itself. Comparing the raw bytes of j in most significant byte
+ * order is equivalent to performing a single precision floating point
+ * comparison on the underlying bits (ignoring NaN comparisons, as NaNs don't
+ * compare equal to anything when performing floating point comparisons).
+ *
+ * The resulting integer is then converted into a byte array by serializing + * the integer one byte at a time in most significant byte order. The + * serialized integer is prefixed by a single header byte. All serialized + * values are 5 bytes in length. + *
+ */ +@InterfaceAudience.Public +@InterfaceStability.Evolving +public class OrderedBytes { + + /* + * The following constant values are used by encoding implementations + */ + + public static final byte TERM = 0x00; + public static final byte NULL = 0x05; + public static final byte NEG_INF = 0x07; + public static final byte NEG_LARGE = 0x08; + public static final byte NEG_MED_MIN = 0x09; + public static final byte NEG_MED_MAX = 0x13; + public static final byte NEG_SMALL = 0x14; + public static final byte ZERO = 0x15; + public static final byte POS_SMALL = 0x16; + public static final byte POS_MED_MIN = 0x17; + public static final byte POS_MED_MAX = 0x21; + public static final byte POS_LARGE = 0x22; + public static final byte POS_INF = 0x23; + public static final byte NAN = 0x25; + public static final byte FIXED_INT32 = 0x27; + public static final byte FIXED_INT64 = 0x28; + public static final byte FIXED_FLOAT32 = 0x30; + public static final byte FIXED_FLOAT64 = 0x31; + public static final byte TEXT = 0x33; + public static final byte BLOB_VAR = 0x35; + public static final byte BLOB_COPY = 0x36; + + public static final Charset UTF8 = Charset.forName("UTF-8"); + + // constants used for numeric {en,de}coding + private static final BigDecimal E8 = BigDecimal.valueOf(1e8); + private static final BigDecimal E32 = BigDecimal.valueOf(1e32); + private static final BigDecimal EN2 = BigDecimal.valueOf(1e-2); + private static final BigDecimal EN10 = BigDecimal.valueOf(1e-10); + + /** + * Perform unsigned comparison between two long values. Conforms to the same + * interface as {@link Comparator#compare(Object, Object)}. + */ + private static int unsignedCmp(long x1, long x2) { + int cmp; + if ((cmp = (x1 < x2 ? -1 : (x1 == x2 ? 0 : 1))) == 0) return 0; + // invert the result when either value is negative + if ((x1 < 0) != (x2 < 0)) return -cmp; + return cmp; + } + + /** + * Write a 32-bit unsigned integer todst as 4 big-endian
+ * bytes.
+ * @return incremented offset.
+ */
+ private static int putUint32(byte[] dst, int offset, int val) {
+ dst[offset++] = (byte) (val >>> 24);
+ dst[offset++] = (byte) (val >>> 16);
+ dst[offset++] = (byte) (val >>> 8);
+ dst[offset++] = (byte) val;
+ return offset;
+ }
+
+ /**
+ * Encode an unsigned 64-bit integer val into dst. Compliment the
+ * encoded value when comp is true.
+ * @return incremented offset;
+ */
+ @VisibleForTesting
+ static int putVaruint64(byte[] dst, int offset, long val, boolean comp) {
+ int w, y, start = offset;
+ Order ord = comp ? DESCENDING : ASCENDING;
+ if (-1 == unsignedCmp(val, 241L)) {
+ dst[offset++] = (byte) val;
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ if (-1 == unsignedCmp(val, 2288L)) {
+ y = (int) (val - 240);
+ dst[offset++] = (byte) (y / 256 + 241);
+ dst[offset++] = (byte) (y % 256);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ if (-1 == unsignedCmp(val, 67824L)) {
+ y = (int) (val - 2288);
+ dst[offset++] = (byte) 249;
+ dst[offset++] = (byte) (y / 256);
+ dst[offset++] = (byte) (y % 256);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ y = (int) (val & 0xffffffff);
+ w = (int) (val >>> 32);
+ if (w == 0) {
+ if (-1 == unsignedCmp(y, 16777216L)) {
+ dst[offset++] = (byte) 250;
+ dst[offset++] = (byte) (y >>> 16);
+ dst[offset++] = (byte) (y >>> 8);
+ dst[offset++] = (byte) y;
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ dst[offset++] = (byte) 251;
+ offset = putUint32(dst, offset, y);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ if (-1 == unsignedCmp(w, 256L)) {
+ dst[offset++] = (byte) 252;
+ dst[offset++] = (byte) w;
+ offset = putUint32(dst, offset, y);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ if (-1 == unsignedCmp(w, 65536L)) {
+ dst[offset++] = (byte) 253;
+ dst[offset++] = (byte) (w >>> 8);
+ dst[offset++] = (byte) w;
+ offset = putUint32(dst, offset, y);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ if (-1 == unsignedCmp(w, 16777216L)) {
+ dst[offset++] = (byte) 254;
+ dst[offset++] = (byte) (w >>> 16);
+ dst[offset++] = (byte) (w >>> 8);
+ dst[offset++] = (byte) w;
+ offset = putUint32(dst, offset, y);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+ dst[offset++] = (byte) 255;
+ offset = putUint32(dst, offset, w);
+ offset = putUint32(dst, offset, y);
+ ord.apply(dst, start, offset - start);
+ return offset;
+ }
+
+ /**
+ * Skip offset forward over an encoded varu64 value.
+ * @param src source buffer
+ * @param offset position in src at which to start.
+ * @param comp if true, parse the compliment of the value.
+ * @return updated value of offset
+ */
+ @VisibleForTesting
+ static int skipVaruint64(byte[] src, int offset, boolean comp) {
+ int a0 = (comp ? DESCENDING : ASCENDING).apply(src[offset]) & 0xff;
+ if (a0 <= 240) return offset + 1;
+ if (a0 >= 241 && a0 <= 248) return offset + 2;
+ if (a0 == 249) return offset + 3;
+ if (a0 == 250) return offset + 4;
+ if (a0 == 251) return offset + 5;
+ if (a0 == 252) return offset + 6;
+ if (a0 == 253) return offset + 7;
+ if (a0 == 254) return offset + 8;
+ if (a0 == 255) return offset + 9;
+ throw new IllegalArgumentException("unexpected value in first byte: 0x"
+ + Long.toHexString(src[offset]));
+ }
+
+ /**
+ * Decode a sequence of bytes in buff as an unsigned 64-bit
+ * integer. Compliment the encoded value when comp is true.
+ * @return the decoded value.
+ */
+ @VisibleForTesting
+ static long getVaruint64(byte[] buff, int offset, boolean comp) {
+ assert skipVaruint64(buff, offset, comp) <= buff.length;
+ long ret;
+ Order ord = comp ? DESCENDING : ASCENDING;
+ byte x = buff[offset++];
+ int a0 = ord.apply(x) & 0xff, a1, a2, a3, a4, a5, a6, a7, a8;
+ if (-1 == unsignedCmp(a0, 241)) {
+ return a0;
+ }
+ x = buff[offset++];
+ a1 = ord.apply(x) & 0xff;
+ if (-1 == unsignedCmp(a0, 249)) {
+ return (a0 - 241) * 256 + a1 + 240;
+ }
+ x = buff[offset++];
+ a2 = ord.apply(x) & 0xff;
+ if (a0 == 249) {
+ return 2288 + 256 * a1 + a2;
+ }
+ x = buff[offset++];
+ a3 = ord.apply(x) & 0xff;
+ if (a0 == 250) {
+ return (a1 << 16) | (a2 << 8) | a3;
+ }
+ x = buff[offset++];
+ a4 = ord.apply(x) & 0xff;
+ ret = (((long) a1) << 24) | (a2 << 16) | (a3 << 8) | a4;
+ if (a0 == 251) {
+ return ret;
+ }
+ x = buff[offset++];
+ a5 = ord.apply(x) & 0xff;
+ if (a0 == 252) {
+ return (ret << 8) | a5;
+ }
+ x = buff[offset++];
+ a6 = ord.apply(x) & 0xff;
+ if (a0 == 253) {
+ return (ret << 16) | (a5 << 8) | a6;
+ }
+ x = buff[offset++];
+ a7 = ord.apply(x) & 0xff;
+ if (a0 == 254) {
+ return (ret << 24) | (a5 << 16) | (a6 << 8) | a7;
+ }
+ x = buff[offset++];
+ a8 = ord.apply(x) & 0xff;
+ return (ret << 32) | (((long) a5) << 24) | (a6 << 16) | (a7 << 8) | a8;
+ }
+
+ /**
+ * Read significand digits from buff according to the magnitude
+ * of e.
+ * @param buff The source from which to read encoded digits.
+ * @param e The magnitude of the first digit read.
+ * @param comp Treat encoded bytes as compliments when comp is true.
+ * @return The decoded value.
+ */
+ private static BigDecimal decodeSignificand(byte[] buff, int offset, int e, boolean comp) {
+ // TODO: can this be made faster?
+ BigDecimal m = BigDecimal.ZERO;
+ e--;
+ for (;; offset++) {
+ // base-100 digits are encoded as val * 2 + 1 except for the termination digit.
+ m = m.add( // m +=
+ new BigDecimal(BigInteger.ONE, e * -2).multiply( // 100 ^ p * [decoded digit]
+ BigDecimal.valueOf(((comp ? DESCENDING : ASCENDING).apply(buff[offset]) & 0xff) / 2)));
+ e--;
+ // detect termination digit
+ if (((comp ? DESCENDING : ASCENDING).apply(buff[offset]) & 1) == 0) {
+ break;
+ }
+ }
+ return m;
+ }
+
+ /**
+ * Skip buff over the significand bytes.
+ * @return updated offset.
+ */
+ private static int skipSignificand(byte[] buff, int offset, boolean comp) {
+ while (((comp ? DESCENDING : ASCENDING).apply(buff[offset++]) & 1) != 0)
+ ;
+ return offset;
+ }
+
+ /**
+ * Encode the small magnitude floating point number val using
+ * the key encoding. The caller guarantees that 1.0 > abs(val) > 0.0.
+ *
+ * A floating point value is encoded as an integer exponent E
+ * and a mantissa M. The original value is equal to
+ * (M * 100^E). E is set to the smallest value
+ * possible without making M greater than or equal to 1.0.
+ *
+ * For this routine, E will always be zero or negative, since
+ * the original value is less than one. The encoding written by this routine
+ * is the ones-complement of the varint of the negative of E
+ * followed by the mantissa:
+ *
+ *
+ * Encoding: ~-E M + *+ * + * @param buff The destination to which encoded digits are written. + * @param val The value to encode. + * @return incremented offset. + */ + private static int encodeNumericSmall(byte[] buff, int offset, BigDecimal val) { + // TODO: this can be done faster? + // assert 1.0 > abs(val) > 0.0 + BigDecimal abs = val.abs(); + assert BigDecimal.ZERO.compareTo(abs) < 0 && BigDecimal.ONE.compareTo(abs) > 0; + boolean isNeg = val.signum() == -1; + int e = 0, d, startM; + + if (isNeg) { /* Small negative number: 0x14, -E, ~M */ + buff[offset++] = NEG_SMALL; + } else { /* Small positive number: 0x16, ~-E, M */ + buff[offset++] = POS_SMALL; + } + + // normalize abs(val) to determine E + while (abs.compareTo(EN10) < 0) { abs = abs.movePointRight(8); e += 4; } + while (abs.compareTo(EN2) < 0) { abs = abs.movePointRight(2); e++; } + + offset = putVaruint64(buff, offset, e, !isNeg); // encode appropriate E value. + + // encode M by peeling off centimal digits, encoding x as 2x+1 + startM = offset; + for (int i = 0; i < 18 && abs.compareTo(BigDecimal.ZERO) != 0; i++) { + abs = abs.movePointRight(2); + d = abs.intValue(); + buff[offset++] = (byte) ((2 * d + 1) & 0xff); + abs = abs.subtract(BigDecimal.valueOf(d)); + } + buff[offset - 1] &= 0xfe; // terminal digit should be 2x + if (isNeg) DESCENDING.apply(buff, startM, offset - startM); // negative values encoded as ~M + return offset; + } + + /** + * Encode the large magnitude floating point number
val using
+ * the key encoding. The caller guarantees that val will be
+ * finite and abs(val) >= 1.0.
+ *
+ * A floating point value is encoded as an integer exponent E
+ * and a mantissa M. The original value is equal to
+ * (M * 100^E). E is set to the smallest value
+ * possible without making M greater than or equal to 1.0.
+ *
+ * Each centimal digit of the mantissa is stored in a byte. If the value of
+ * the centimal digit is X (hence X>=0 and
+ * X<=99) then the byte value will be 2*X+1 for
+ * every byte of the mantissa, except for the last byte which will be
+ * 2*X+0. The mantissa must be the minimum number of bytes
+ * necessary to represent the value; trailing X==0 digits are
+ * omitted. This means that the mantissa will never contain a byte with the
+ * value 0x00.
+ *
+ * If E > 10, then this routine writes of E as a
+ * varint followed by the mantissa as described above. Otherwise, if
+ * E <= 10, this routine only writes the mantissa and leaves
+ * the E value to be encoded as part of the opening byte of the
+ * field by the calling function.
+ *
+ *
+ * Encoding: M (if E<=10) + * E M (if E>10) + *+ * + * @param buff The destination to which encoded digits are written. + * @param val The value to encode. + * @return updated offset. + */ + private static int encodeNumericLarge(byte[] buff, int offset, BigDecimal val) { + // TODO: this can be done faster + // assert abs(val) >= 1.0 + BigDecimal abs = val.abs(); + assert BigDecimal.ONE.compareTo(abs) <= 0; + boolean isNeg = val.signum() == -1; + int e = 0, d, header = offset, startM; + + if (isNeg) { /* Large negative number: 0x08, ~E, ~M */ + buff[offset++] = NEG_LARGE; + } else { /* Large positive number: 0x22, E, M */ + buff[offset++] = POS_LARGE; + } + + // normalize abs(val) to determine E + while (abs.compareTo(E32) >= 0 && e <= 350) { abs = abs.movePointLeft(32); e +=16; } + while (abs.compareTo(E8) >= 0 && e <= 350) { abs = abs.movePointLeft(8); e+= 4; } + while (abs.compareTo(BigDecimal.ONE) >= 0 && e <= 350) { abs = abs.movePointLeft(2); e++; } + + // encode appropriate header byte and/or E value. + if (e > 10) { /* large number, write out {~,}E */ + offset = putVaruint64(buff, offset, e, isNeg); + } else { + if (isNeg) { /* Medium negative number: 0x13-E, ~M */ + buff[header] = (byte) (NEG_MED_MAX - e); + } else { /* Medium positive number: 0x17+E, M */ + buff[header] = (byte) (POS_MED_MIN + e); + } + } + + // encode M by peeling off centimal digits, encoding x as 2x+1 + startM = offset; + for (int i = 0; i < 18 && abs.compareTo(BigDecimal.ZERO) != 0; i++) { + abs = abs.movePointRight(2); + d = abs.intValue(); + buff[offset++] = (byte) (2 * d + 1); + abs = abs.subtract(BigDecimal.valueOf(d)); + } + + buff[offset - 1] &= 0xfe; // terminal digit should be 2x + if (isNeg) DESCENDING.apply(buff, startM, offset - startM); // negative values encoded as ~M + return offset; + } + + /** + * Encode a numerical value using the variable-length encoding. + * @return updated offset. + */ + public static int encodeNumeric(byte[] buff, int offset, long val, Order ord) { + return encodeNumeric(buff, offset, BigDecimal.valueOf(val), ord); + } + + /** + * Encode a numerical value using the variable-length encoding. + * @return updated offset. + */ + public static int encodeNumeric(byte[] buff, int offset, double val, Order ord) { + if (Double.isNaN(val)) { + buff[offset++] = ord.apply(NAN); + return offset; + } else if (val == Double.NEGATIVE_INFINITY) { + buff[offset++] = ord.apply(NEG_INF); + return offset; + } else if (val == Double.POSITIVE_INFINITY) { + buff[offset++] = ord.apply(POS_INF); + return offset; + } else if (val == 0.0) { + buff[offset++] = ord.apply(ZERO); + return offset; + } else { + return encodeNumeric(buff, offset, BigDecimal.valueOf(val), ord); + } + } + + /** + * Encode a numerical value using the variable-length encoding. + * @return updated offset. + */ + public static int encodeNumeric(byte[] buff, int offset, BigDecimal val, Order ord) { + int start = offset; + if (null == val) { + return encodeNull(buff, offset, ord); + } else if (BigDecimal.ZERO.compareTo(val) == 0) { + buff[offset++] = ord.apply(ZERO); + return offset; + } + BigDecimal abs = val.abs(); + if (BigDecimal.ONE.compareTo(abs) <= 0) { // abs(v) >= 1.0 + offset = encodeNumericLarge(buff, offset, val); + } else { // 1.0 > abs(v) > 0.0 + offset = encodeNumericSmall(buff, offset, val); + } + ord.apply(buff, start, offset - start); + return offset; + } + + /** + * Encode a numerical value using the variable-length encoding. + * @return updated offset. + */ + public static int encodeNumeric(byte[] buff, int offset, Numeric val, Order ord) { + if (null == val) { + return encodeNull(buff, offset, ord); + } else if (val.isInteger()) { + return encodeNumeric(buff, offset, val.longValue(), ord); + } else if (val.isReal()) { + return encodeNumeric(buff, offset, val.doubleValue(), ord); + } else { + return encodeNumeric(buff, offset, val.exactValue(), ord); + } + } + + /** + * Decode a Numerical value from the variable-length encoding. The backing + * array is not modified through use of this method. + */ + public static Numeric decodeNumeric(byte[] buff, int offset) { + byte header = buff[offset++]; + if (header == NULL || header == DESCENDING.apply(NULL)) + return null; + int e = 0; + boolean dsc = (-1 == Integer.signum(header)); + if (dsc) header = DESCENDING.apply(header); + + if (header == NAN) { + return Numeric.NaN; + } else if (header == NEG_INF) { + return Numeric.NEGATIVE_INFINITY; + } else if (header == NEG_LARGE) { /* Large negative number: 0x08, ~E, ~M */ + e = (int) getVaruint64(buff, offset, !dsc); + offset = skipVaruint64(buff, offset, !dsc); + return new Numeric(decodeSignificand(buff, offset, e, !dsc).negate()); + } else if (header >= NEG_MED_MIN && header <= NEG_MED_MAX) { + /* Medium negative number: 0x13-E, ~M */ + e = NEG_MED_MAX - header; + return new Numeric(decodeSignificand(buff, offset, e, !dsc).negate()); + } else if (header == NEG_SMALL) { /* Small negative number: 0x14, -E, ~M */ + e = (int) -getVaruint64(buff, offset, dsc); + offset = skipVaruint64(buff, offset, dsc); + return new Numeric(decodeSignificand(buff, offset, e, !dsc).negate()); + } else if (header == ZERO) { + return Numeric.ZERO; + } else if (header == POS_SMALL) { /* Small positive number: 0x16, ~-E, M */ + e = (int) -getVaruint64(buff, offset, !dsc); + offset = skipVaruint64(buff, offset, !dsc); + return new Numeric(decodeSignificand(buff, offset, e, dsc)); + } else if (header >= POS_MED_MIN && header <= POS_MED_MAX) { + /* Medium positive number: 0x17+E, M */ + e = header - POS_MED_MIN; + return new Numeric(decodeSignificand(buff, offset, e, dsc)); + } else if (header == POS_LARGE) { /* Large positive number: 0x22, E, M */ + e = (int) getVaruint64(buff, offset, dsc); + offset = skipVaruint64(buff, offset, dsc); + return new Numeric(decodeSignificand(buff, offset, e, dsc)); + } else if (header == POS_INF) { + return Numeric.POSITIVE_INFINITY; + } else { + throw new IllegalArgumentException("unexpected value in first byte: 0x" + + Long.toHexString(header)); + } + } + + /** + * Encode a String value. + * @return updated offset. + */ + public static int encodeString(byte[] buff, int offset, String val, Order ord) { + if (null == val) { + return encodeNull(buff, offset, ord); + } + if (val.contains("\u0000")) + throw new IllegalArgumentException("Cannot encode String values containing '\\u0000'"); + int start = offset; + // TODO: is there no way to decode into buff directly? + byte[] bytes = val.getBytes(UTF8); + buff[offset++] = TEXT; + System.arraycopy(bytes, 0, buff, offset, bytes.length); + offset += bytes.length; + buff[offset++] = TERM; + ord.apply(buff, start, offset - start); + return offset; + } + + /** + * Decode a String value. The backing array is not modified through use of + * this method. + */ + public static String decodeString(byte[] buff, int offset) { + byte header = buff[offset++]; + if (header == NULL || header == DESCENDING.apply(NULL)) + return null; + assert header == TEXT || header == DESCENDING.apply(TEXT); + Order ord = header == TEXT ? ASCENDING : DESCENDING; + int start = offset; + byte terminator = ord.apply(TERM); + while (buff[offset++] != terminator) ; + if (DESCENDING == ord) { + byte[] copy = Arrays.copyOfRange(buff, start, offset - 1); + ord.apply(copy); + return new String(copy, UTF8); + } else { + return new String(buff, start, offset - start - 1, UTF8); + } + } + + /** + * Calculate the expected BlobVar encoded length based on unencoded length. + */ + public static int blobVarEncodedLength(int len) { + if (0 == len) + return 2; // 1-byte header + 1-byte terminator + else + return (int) + Math.ceil( + (len * 8) // 8-bits per input byte + / 7.0) // 7-bits of input data per encoded byte, rounded up + + 1; // + 1-byte header + } + + /** + * Calculate the expected BlobVar decoded length based on encoded length. + */ + @VisibleForTesting + static int blobVarDecodedLength(int len) { + return + ((len + - 1) // 1-byte header + * 7) // 7-bits of payload per encoded byte + / 8; // 8-bits per byte + } + + /** + * Encode a Blob value using a modified varint encoding scheme. + *
+ * This format encodes a byte[] value such that no limitations on the input + * value are imposed. The first byte encodes the encoding scheme that + * follows, 0x35. Each encoded byte thereafter has a header bit indicating + * whether there is another encoded byte following. A header bit of '1' + * indicates continuation of the encoding. A header bit of '0' indicates + * this byte encodes the final byte. An empty input value is a special case, + * wherein a NULL byte is used as a termination byte. The remaining 7 bits + * on each encoded byte carry the value payload. + *
+ * @return updated offset. + */ + public static int + encodeBlobVar(byte[] buff, int offset, byte[] val, int voff, int vlen, Order ord) { + if (null == val) { + return encodeNull(buff, offset, ord); + } + // Empty value is null-terminated. All other values are encoded as 7-bits per byte. + assert buff.length - offset >= blobVarEncodedLength(vlen) : "buffer overflow expected."; + int start = offset; + buff[offset++] = BLOB_VAR; + if (0 == vlen) { + buff[offset++] = TERM; + } else { + byte s = 1, t = 0; + for (int i = voff; i < vlen; i++) { + buff[offset++] = (byte) (0x80 | t | ((val[i] & 0xff) >>> s)); + if (s < 7) { + t = (byte) (val[i] << (7 - s)); + s++; + } else { + buff[offset++] = (byte) (0x80 | val[i]); + s = 1; + t = 0; + } + } + if (s > 1) { + buff[offset++] = (byte) (0x7f & t); + } else { + buff[offset - 1] &= 0x7f; + } + } + ord.apply(buff, start, offset - start); + return offset; + } + + /** + * Encode a blob value using a modified varint encoding scheme. + * @return updated offset. + */ + public static int encodeBlobVar(byte[] buff, int offset, byte[] val, Order ord) { + return encodeBlobVar(buff, offset, val, 0, null != val ? val.length : 0, ord); + } + + /** + * Decode a blob value that was encoded using BlobVar encoding. The backing + * array is not modified through use of this method. + */ + public static byte[] decodeBlobVar(byte[] buff, int offset) { + byte header = buff[offset++]; + if (header == NULL || header == DESCENDING.apply(NULL)) + return null; + assert header == BLOB_VAR || header == DESCENDING.apply(BLOB_VAR); + Order ord = BLOB_VAR == header ? ASCENDING : DESCENDING; + int start = offset, end; + if (buff[start] == ord.apply(TERM)) { + // skip empty input buffer. + return new byte[0]; + } + for (end = start; (byte) (ord.apply(buff[end]) & 0x80) != TERM; end++) ; + end++; // increment end to 1-past last byte + // create ret buffer using length of encoded data + 1 (header byte) + byte[] ret = new byte[blobVarDecodedLength(end - start + 1)]; + int roff = 0, s = 6; + byte t = (byte) ((ord.apply(buff[start]) << 1) & 0xff); + for (int i = start + 1; i < end; i++) { + if (s == 7) { + ret[roff++] = (byte) (t | (ord.apply(buff[i]) & 0x7f)); + i++; + } else { + ret[roff++] = (byte) (t | ((ord.apply(buff[i]) & 0x7f) >>> s)); + } + if (i == end) break; + t = (byte) ((ord.apply(buff[i]) << 8 - s) & 0xff); + s = s == 1 ? 7 : s - 1; + } + assert t == 0 : "Unexpected bits remaining after decoding blob."; + return ret; + } + + /** + * Encode a Blob value as a byte-for-byte copy. + * @return updated offset. + */ + public static int encodeBlobCopy(byte[] buff, int offset, byte[] val, int voff, int vlen, + Order ord) { + if (null == val) { + offset = encodeNull(buff, offset, ord); + if (DESCENDING == ord) { + // DESCENDING ordered BlobCopy requires a termination bit to preserve + // sort-order semantics of null values. + buff[offset++] = ord.apply(TERM); + } + return offset; + } + // Blobs as final entry in a compound key are written unencoded. + int overhead = ASCENDING == ord ? 1 : 2; + assert buff.length - offset >= vlen + overhead; + for (int i = voff; i < voff + vlen; i++) { + if (val[i] == 0x00) + throw new IllegalArgumentException("0x00 bytes not permitted in value."); + } + int start = offset; + buff[offset++] = BLOB_COPY; + System.arraycopy(val, voff, buff, offset, vlen); + offset += vlen; + // DESCENDING ordered BlobCopy requires a termination bit to preserve + // sort-order semantics of null values. + if (DESCENDING == ord) buff[offset++] = TERM; + ord.apply(buff, start, offset - start); + return offset; + } + + /** + * Encode a Blob value as a byte-for-byte copy. + * @return updated offset. + */ + public static int encodeBlobCopy(byte[] buff, int offset, byte[] val, Order ord) { + return encodeBlobCopy(buff, offset, val, 0, null != val ? val.length : 0, ord); + } + + /** + * Decode a Blob value, byte-for-byte copy. The backing array is not + * modified through use of this method. + */ + public static byte[] decodeBlobCopy(byte[] buff, int offset) { + byte header = buff[offset++]; + if (header == NULL || header == DESCENDING.apply(NULL)) { + return null; + } + + assert header == BLOB_COPY || header == DESCENDING.apply(BLOB_COPY); + Order ord = header == BLOB_COPY ? ASCENDING : DESCENDING; + int length = buff.length - offset - (ASCENDING == ord ? 0 : 1); + byte[] ret = new byte[length]; + System.arraycopy(buff, offset, ret, 0, length); + ord.apply(ret, 0, ret.length); + return ret; + } + + /** + * Encode a null value. + * @return updated offset. + */ + public static int encodeNull(byte[] buff, int offset, Order ord) { + buff[offset++] = ord.apply(NULL); + return offset; + } + + /** + * Encode anint32 value using the fixed-length encoding.
+ * @return updated offset.
+ */
+ public static int encodeInt32(byte[] buff, int offset, int val, Order ord) {
+ int start = offset;
+ buff[offset++] = FIXED_INT32;
+ buff[offset++] = (byte) ((val >> 24) ^ 0x80);
+ buff[offset++] = (byte) (val >> 16);
+ buff[offset++] = (byte) (val >> 8);
+ buff[offset++] = (byte) val;
+ ord.apply(buff, start, offset - start);
+ return offset;
+ }
+
+ /**
+ * Decode an int32 value. The backing array is not modified
+ * through use of this method.
+ */
+ public static int decodeInt32(byte[] buff, int offset) {
+ byte header = buff[offset++];
+ assert header == FIXED_INT32 || header == DESCENDING.apply(FIXED_INT32);
+ Order ord = header == 0x27 ? ASCENDING : DESCENDING;
+ int val = (ord.apply(buff[offset++]) ^ 0x80) & 0xff;
+ for (int i = 1; i < 4; i++) {
+ val = (val << 8) + (ord.apply(buff[offset++]) & 0xff);
+ }
+ return val;
+ }
+
+ /**
+ * Encode an int64 value using the fixed-length encoding.
+ * @return updated offset.
+ */
+ public static int encodeInt64(byte[] buff, int offset, long val, Order ord) {
+ int start = offset;
+ buff[offset++] = FIXED_INT64;
+ buff[offset++] = (byte) ((val >> 56) ^ 0x80);
+ buff[offset++] = (byte) (val >> 48);
+ buff[offset++] = (byte) (val >> 40);
+ buff[offset++] = (byte) (val >> 32);
+ buff[offset++] = (byte) (val >> 24);
+ buff[offset++] = (byte) (val >> 16);
+ buff[offset++] = (byte) (val >> 8);
+ buff[offset++] = (byte) val;
+ ord.apply(buff, start, offset - start);
+ return offset;
+ }
+
+ /**
+ * Decode an int64 value. The backing array is not modified
+ * through use of this method.
+ */
+ public static long decodeInt64(byte[] buff, int offset) {
+ byte header = buff[offset++];
+ assert header == FIXED_INT64 || header == DESCENDING.apply(FIXED_INT64);
+ Order ord = header == FIXED_INT64 ? ASCENDING : DESCENDING;
+ long val = (ord.apply(buff[offset++]) ^ 0x80) & 0xff;
+ for (int i = 1; i < 8; i++) {
+ val = (val << 8) + (ord.apply(buff[offset++]) & 0xff);
+ }
+ return val;
+ }
+
+ /**
+ * Encode a 32-bit floating point value using the fixed-length encoding.
+ * @return updated offset.
+ * @see #decodeFloat32(byte[], int)
+ */
+ public static int encodeFloat32(byte[] buff, int offset, float val, Order ord) {
+ int start = offset;
+ int i = Float.floatToIntBits(val);
+ i ^= ((i >> Integer.SIZE - 1) | Integer.MIN_VALUE);
+ buff[offset++] = FIXED_FLOAT32;
+ buff[offset++] = (byte) (i >> 24);
+ buff[offset++] = (byte) (i >> 16);
+ buff[offset++] = (byte) (i >> 8);
+ buff[offset++] = (byte) i;
+ ord.apply(buff, start, offset - start);
+ return offset;
+ }
+
+ /**
+ * Decode a 32-bit floating point value using the fixed-length encoding.
+ * @see #encodeFloat32(byte[], int, float, Order)
+ */
+ public static float decodeFloat32(byte[] buff, int offset) {
+ byte header = buff[offset++];
+ assert header == FIXED_FLOAT32 || header == DESCENDING.apply(FIXED_FLOAT32);
+ Order ord = header == FIXED_FLOAT32 ? ASCENDING : DESCENDING;
+ int val = ord.apply(buff[offset++]) & 0xff;
+ for (int i = 1; i < 4; i++) {
+ val = (val << 8) + (ord.apply(buff[offset++]) & 0xff);
+ }
+ val ^= (~val >> Integer.SIZE - 1) | Integer.MIN_VALUE;
+ return Float.intBitsToFloat(val);
+ }
+
+ /**
+ * Encode a 64-bit floating point value using the fixed-length encoding.
+ * + * This format ensures the following total ordering of floating point + * values: Double.NEGATIVE_INFINITY < -Double.MAX_VALUE < ... < + * -Double.MIN_VALUE < -0.0 < +0.0; < Double.MIN_VALUE < ... + * < Double.MAX_VALUE < Double.POSITIVE_INFINITY < Double.NaN + *
+ * Floating point numbers are encoded as specified in IEEE 754. A 64-bit + * double precision float consists of a sign bit, 11-bit unsigned exponent + * encoded in offset-1023 notation, and a 52-bit significand. The format is + * described further in the Double Precision + * Floating Point Wikipedia page + *+ * The value of a normal float is -1 sign bit × + * 2exponent - 1023 × 1.significand + *
+ *+ * The IEE754 floating point format already preserves sort ordering for + * positive floating point numbers when the raw bytes are compared in most + * significant byte order. This is discussed further at http://www.cygnus-software.com/papers/comparingfloats/comparingfloats. + * htm + *
+ *+ * Thus, we need only ensure that negative numbers sort in the the exact + * opposite order as positive numbers (so that say, negative infinity is + * less than negative 1), and that all negative numbers compare less than + * any positive number. To accomplish this, we invert the sign bit of all + * floating point numbers, and we also invert the exponent and significand + * bits if the floating point number was negative. + *
+ *
+ * More specifically, we first store the floating point bits into a 64-bit
+ * long l using {@link Double#doubleToLongBits}. This method
+ * collapses all NaNs into a single, canonical NaN value but otherwise
+ * leaves the bits unchanged. We then compute
+ *
+ * l ˆ= (l >> (Long.SIZE - 1)) | Long.MIN_SIZE + *+ *
+ * which inverts the sign bit and XOR's all other bits with the sign bit
+ * itself. Comparing the raw bytes of l in most significant
+ * byte order is equivalent to performing a double precision floating point
+ * comparison on the underlying bits (ignoring NaN comparisons, as NaNs
+ * don't compare equal to anything when performing floating point
+ * comparisons).
+ *
+ * The resulting long integer is then converted into a byte array by + * serializing the long one byte at a time in most significant byte order. + * The serialized integer is prefixed by a single header byte. All + * serialized values are 9 bytes in length. + *
+ * @return updated offset. + */ + public static int encodeFloat64(byte[] buff, int offset, double val, Order ord) { + int start = offset; + long lng = Double.doubleToLongBits(val); + lng ^= ((lng >> Long.SIZE - 1) | Long.MIN_VALUE); + buff[offset++] = FIXED_FLOAT64; + buff[offset++] = (byte) (lng >> 56); + buff[offset++] = (byte) (lng >> 48); + buff[offset++] = (byte) (lng >> 40); + buff[offset++] = (byte) (lng >> 32); + buff[offset++] = (byte) (lng >> 24); + buff[offset++] = (byte) (lng >> 16); + buff[offset++] = (byte) (lng >> 8); + buff[offset++] = (byte) lng; + ord.apply(buff, start, offset - start); + return offset; + } + + /** + * Decode a 64-bit floating point value using the fixed-length encoding. + * @see #encodeFloat64(byte[], int, double, Order) + */ + public static double decodeFloat64(byte[] buff, int offset) { + byte header = buff[offset++]; + assert header == FIXED_FLOAT64 || header == DESCENDING.apply(FIXED_FLOAT64); + Order ord = header == FIXED_FLOAT64 ? ASCENDING : DESCENDING; + long val = ord.apply(buff[offset++]) & 0xff; + for (int i = 1; i < 8; i++) { + val = (val << 8) + (ord.apply(buff[offset++]) & 0xff); + } + val ^= (~val >> Long.SIZE - 1) | Long.MIN_VALUE; + return Double.longBitsToDouble(val); + } + + /** + * Skip offset forward over one encoded value. + * @return updated offset. + */ + public static int skip(byte[] buff, int offset) { + byte x = buff[offset++]; + Order ord = (-1 == Integer.signum(x)) ? DESCENDING : ASCENDING; + x = ord.apply(x); + + switch (x) { + case NULL: + case NEG_INF: + return offset; + case NEG_LARGE: /* Large negative number: 0x08, ~E, ~M */ + offset = skipVaruint64(buff, offset, DESCENDING != ord); + return skipSignificand(buff, offset, DESCENDING != ord); + case NEG_MED_MIN: /* Medium negative number: 0x13-E, ~M */ + case NEG_MED_MIN + 0x01: + case NEG_MED_MIN + 0x02: + case NEG_MED_MIN + 0x03: + case NEG_MED_MIN + 0x04: + case NEG_MED_MIN + 0x05: + case NEG_MED_MIN + 0x06: + case NEG_MED_MIN + 0x07: + case NEG_MED_MIN + 0x08: + case NEG_MED_MIN + 0x09: + case NEG_MED_MAX: + return skipSignificand(buff, offset, DESCENDING != ord); + case NEG_SMALL: /* Small negative number: 0x14, -E, ~M */ + offset = skipVaruint64(buff, offset, DESCENDING == ord); + return skipSignificand(buff, offset, DESCENDING != ord); + case ZERO: + return offset; + case POS_SMALL: /* Small positive number: 0x16, ~-E, M */ + offset = skipVaruint64(buff, offset, DESCENDING != ord); + return skipSignificand(buff, offset, DESCENDING == ord); + case POS_MED_MIN: /* Medium positive number: 0x17+E, M */ + case POS_MED_MIN + 0x01: + case POS_MED_MIN + 0x02: + case POS_MED_MIN + 0x03: + case POS_MED_MIN + 0x04: + case POS_MED_MIN + 0x05: + case POS_MED_MIN + 0x06: + case POS_MED_MIN + 0x07: + case POS_MED_MIN + 0x08: + case POS_MED_MIN + 0x09: + case POS_MED_MAX: + return skipSignificand(buff, offset, DESCENDING == ord); + case POS_LARGE: /* Large positive number: 0x22, E, M */ + offset = skipVaruint64(buff, offset, DESCENDING == ord); + return skipSignificand(buff, offset, DESCENDING == ord); + case POS_INF: + return offset; + case NAN: + return offset; + case FIXED_INT32: + return offset + 4; + case FIXED_INT64: + return offset + 8; + case FIXED_FLOAT32: + return offset + 4; + case FIXED_FLOAT64: + return offset + 8; + case TEXT: + // for null-terminated values, skip to the end. + do { + x = ord.apply(buff[offset++]); + } while (x != TERM); + return offset; + case BLOB_VAR: + // read until we find a 0 in the MSB + do { + x = ord.apply(buff[offset++]); + } while ((byte) (x & 0x80) != TERM); + return offset; + case BLOB_COPY: + if (Order.DESCENDING == ord) { + // if descending, read to termination byte. + do { + x = ord.apply(buff[offset++]); + } while (x != TERM); + return offset; + } else { + // otherwise, just skip to the end. + return buff.length; + } + default: + throw new IllegalArgumentException("unexpected value in first byte: 0x" + + Long.toHexString(x)); + } + } + + /** + * Return the number of encoded entries remaining inbuff. The
+ * state of buff is not modified through use of this method.
+ */
+ public static int length(byte[] buff, int offset) {
+ int cnt = 0;
+ for (; offset != buff.length; offset = skip(buff, offset), cnt++) ;
+ return cnt;
+ }
+}
diff --git a/hbase-common/src/test/java/org/apache/hadoop/hbase/util/TestOrderedBytes.java b/hbase-common/src/test/java/org/apache/hadoop/hbase/util/TestOrderedBytes.java
new file mode 100644
index 0000000..a950c27
--- /dev/null
+++ b/hbase-common/src/test/java/org/apache/hadoop/hbase/util/TestOrderedBytes.java
@@ -0,0 +1,755 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+package org.apache.hadoop.hbase.util;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.math.BigDecimal;
+import java.util.Arrays;
+import java.util.Collections;
+
+import org.apache.hadoop.hbase.SmallTests;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category(SmallTests.class)
+public class TestOrderedBytes {
+
+ // integer constants for testing Numeric code paths
+ static final Long[] I_VALS =
+ { 0L, 1L, 10L, 99L, 100L, 1234L, 9999L, 10000L, 10001L, 12345L, 123450L, Long.MAX_VALUE };
+ static final int[] I_LENGTHS = { 1, 2, 2, 2, 2, 3, 3, 2, 4, 4, 4, 11 };
+
+ // real constants for testing Numeric code paths
+ static final Double[] D_VALS =
+ { 0.0, 0.00123, 0.0123, 0.123, 1.0, 10.0, 12.345, 99.0, 99.01, 99.0001, 100.0, 100.01,
+ 100.1, 1234.0, 1234.5, 9999.0, 9999.000001, 9999.000009, 9999.00001, 9999.00009,
+ 9999.000099, 9999.0001, 9999.001, 9999.01, 9999.1, 10000.0, 10001.0, 12345.0, 123450.0,
+ Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, Double.NaN, Double.MAX_VALUE };
+ static final int[] D_LENGTHS =
+ { 1, 4, 4, 4, 2, 2, 4, 2, 3, 4, 2, 4,
+ 4, 3, 4, 3, 6, 6, 6, 6,
+ 6, 5, 5, 4, 4, 2, 4, 4, 4,
+ 1, 1, 1, 11 };
+
+ // fill in other gaps in Numeric code paths
+ static final Numeric[] N_VALS =
+ { null, new Numeric(Long.MAX_VALUE), new Numeric(Long.MIN_VALUE),
+ new Numeric(Double.MAX_VALUE), new Numeric(Double.MIN_VALUE),
+ new Numeric(BigDecimal.valueOf(Long.MAX_VALUE).multiply(BigDecimal.valueOf(100))) };
+ static final int[] N_LENGTHS =
+ { 1, 11, 11, 11, 4, 12 };
+
+ /*
+ * This is the smallest difference between two doubles in D_VALS
+ */
+ static final double MIN_EPSILON = 0.000001;
+
+ /**
+ * Expected lengths of equivalent values should match
+ */
+ @Test
+ public void testVerifyTestIntegrity() {
+ for (int i = 0; i < I_VALS.length; i++) {
+ for (int d = 0; d < D_VALS.length; d++) {
+ if (Math.abs(I_VALS[i] - D_VALS[d]) < MIN_EPSILON) {
+ assertEquals(
+ "Test inconsistency detected: expected lengths for " + I_VALS[i] + " do not match.",
+ I_LENGTHS[i], D_LENGTHS[d]);
+ }
+ }
+ }
+ }
+
+ /**
+ * Tests the variable uint64 encoding.
+ *
+ * Building sqlite4 with -DVARINT_TOOL provides this reference:
+ * $ ./varint_tool 240 2287 67823 16777215 4294967295 1099511627775
+ * 281474976710655 72057594037927935 18446744073709551615
+ *
+ * 240 = f0
+ * 2287 = f8ff
+ * 67823 = f9ffff
+ * 16777215 = faffffff
+ * 4294967295 = fbffffffff
+ * 1099511627775 = fcffffffffff
+ * 281474976710655 = fdffffffffffff
+ * 72057594037927935 = feffffffffffffff
+ * 9223372036854775807 = ff7fffffffffffffff (Long.MAX_VAL)
+ * 9223372036854775808 = ff8000000000000000 (Long.MIN_VAL)
+ * 18446744073709551615 = ffffffffffffffffff