コード例 #1
0
ファイル: GroupByHash.java プロジェクト: Ravion/Presto-1
  private static boolean valueEquals(
      Type type, Slice leftSlice, int leftOffset, Slice rightSlice, int rightOffset) {
    // check if null flags are the same
    boolean leftIsNull = leftSlice.getByte(leftOffset) != 0;
    boolean rightIsNull = rightSlice.getByte(rightOffset) != 0;
    if (leftIsNull != rightIsNull) {
      return false;
    }

    // if values are both null, they are equal
    if (leftIsNull) {
      return true;
    }

    if (type == Type.FIXED_INT_64 || type == Type.DOUBLE) {
      long leftValue = leftSlice.getLong(leftOffset + SIZE_OF_BYTE);
      long rightValue = rightSlice.getLong(rightOffset + SIZE_OF_BYTE);
      return leftValue == rightValue;
    } else if (type == Type.BOOLEAN) {
      boolean leftValue = leftSlice.getByte(leftOffset + SIZE_OF_BYTE) != 0;
      boolean rightValue = rightSlice.getByte(rightOffset + SIZE_OF_BYTE) != 0;
      return leftValue == rightValue;
    } else if (type == Type.VARIABLE_BINARY) {
      int leftLength = getVariableBinaryLength(leftSlice, leftOffset);
      int rightLength = getVariableBinaryLength(rightSlice, rightOffset);
      return leftSlice.equals(
          leftOffset + SIZE_OF_BYTE + SIZE_OF_INT,
          leftLength,
          rightSlice,
          rightOffset + SIZE_OF_BYTE + SIZE_OF_INT,
          rightLength);
    } else {
      throw new IllegalArgumentException("Unsupported type " + type);
    }
  }
コード例 #2
0
ファイル: StringFunctions.java プロジェクト: JinGeek/presto
  @Description("returns index of first occurrence of a substring (or 0 if not found)")
  @ScalarFunction("strpos")
  @SqlType(BigintType.class)
  public static long stringPosition(
      @SqlType(VarcharType.class) Slice string, @SqlType(VarcharType.class) Slice substring) {
    if (substring.length() > string.length()) {
      return 0;
    }

    for (int i = 0; i <= (string.length() - substring.length()); i++) {
      if (string.equals(i, substring.length(), substring, 0, substring.length())) {
        return i + 1;
      }
    }

    return 0;
  }
コード例 #3
0
ファイル: StringFunctions.java プロジェクト: JinGeek/presto
  // TODO: Implement a more efficient string search
  @Nullable
  @Description("splits a string by a delimiter and returns the specified field (counting from one)")
  @ScalarFunction
  @SqlType(VarcharType.class)
  public static Slice splitPart(
      @SqlType(VarcharType.class) Slice string,
      @SqlType(VarcharType.class) Slice delimiter,
      @SqlType(BigintType.class) long index) {
    checkArgument(index > 0, "Index must be greater than zero");

    if (delimiter.length() == 0) {
      if (index > string.length()) {
        // index is too big, null is returned
        return null;
      }
      return string.slice((int) (index - 1), 1);
    }

    int previousIndex = 0;
    int matchCount = 0;

    for (int i = 0; i <= (string.length() - delimiter.length()); i++) {
      if (string.equals(i, delimiter.length(), delimiter, 0, delimiter.length())) {
        matchCount++;
        if (matchCount == index) {
          return string.slice(previousIndex, i - previousIndex);
        }
        // noinspection AssignmentToForLoopParameter
        i += (delimiter.length() - 1);
        previousIndex = i + 1;
      }
    }

    if (matchCount == index - 1) {
      // returns last section of the split
      return string.slice(previousIndex, string.length() - previousIndex);
    }

    // index is too big, null is returned
    return null;
  }