Struct FieldEncoding 

pub struct FieldEncoding(/* private fields */);

Values for the encoding byte of a field definition.

The low 5 bits of the encoding byte contain the field’s encoding. The encoding indicates the following information about the field:

• How the decoder should determine the size of the field. For example, Value32 indicates a 4-byte field, Value128 indicates a 16-byte field, ZStringChar8 indicates that the field ends at the first char8 unit with value 0, and BinaryLength16Char8 indicates that the first 16 bits of the field are the uint16 Length and that the subsequent Length char8 units of the field are the field data.

• How the field should be formatted if the field’s format is Default (0), unrecognized, or unsupported. For example, a Value32 encoding with Default or unrecognized format should be treated as if it had UnsignedInt format. A StringLength16Char8 encoding with Default or unrecognized format should be treated as if it had StringUtf format. A BinaryLength16Char8 encoding with Default or unrecognized format should be treated as if it had HexBytes format.

The StringLength16Char8 and BinaryLength16Char8 encodings are special. These encodings can be used with both variable-length (e.g. HexBytes and String) formats as well as with fixed-length (e.g. UnsignedInt, Float, IPAddress) formats. When used with fixed-length formats, the semantics depend on the field’s variable Length (as determined from the first 16 bits of the field):

• If the Length is 0, the field is formatted as null. For example, a field with encoding = BinaryLength16Char8, format = SignedInt, and Length = 0 would be formatted as a null value.

• If the Length is appropriate for the format, the field is formatted as if it had the Value8, Value16, Value32, Value64, or Value128 encoding corresponding to its size. For example, a field with encoding = BinaryLength16Char8, format = SignedInt, and Length = 4 would be formatted as an int32 field.

• If the Length is not appropriate for the format, the field is formatted as if it had the default format for the encoding. For example, a field with encoding = BinaryLength16Char8, format = SignedInt, and Length = 16 would be formatted as a HexBytes field since 16 is not a supported size for the SignedInt format and the default format for BinaryLength16Char8 is HexBytes.

The top 3 bits of the field encoding byte are flags:

• CArrayFlag indicates that this field is a constant-length array, with the element count specified as a 16-bit value in the event metadata (must not be 0).

• VArrayFlag indicates that this field is a variable-length array, with the element count specified as a 16-bit value in the event payload (immediately before the array elements, may be 0).

• ChainFlag indicates that a format byte is present after the encoding byte. If ChainFlag is not set, the format byte is omitted and is assumed to be 0.

Setting both CArrayFlag and VArrayFlag is invalid (reserved).

Implementations

impl FieldEncoding

pub const Invalid: FieldEncoding

Invalid encoding value.

pub const Struct: FieldEncoding

0-byte value, logically groups subsequent N fields, N = format & 0x7F, N must not be 0.

pub const Value8: FieldEncoding

1-byte value, default format UnsignedInt.

Usable formats: UnsignedInt, SignedInt, HexInt, Boolean, HexBytes, String8.

pub const Value16: FieldEncoding

2-byte value, default format UnsignedInt.

Usable formats: UnsignedInt, SignedInt, HexInt, Boolean, HexBytes, StringUtf, Port.

pub const Value32: FieldEncoding

4-byte value, default format UnsignedInt.

Usable formats: UnsignedInt, SignedInt, HexInt, Errno, Pid, Time, Boolean, Float, HexBytes, StringUtf, IPv4.

pub const Value64: FieldEncoding

8-byte value, default format UnsignedInt.

Usable formats: UnsignedInt, SignedInt, HexInt, Time, Float, HexBytes.

pub const Value128: FieldEncoding

16-byte value, default format HexBytes.

Usable formats: HexBytes, Uuid, IPv6.

pub const ZStringChar8: FieldEncoding

zero-terminated uint8[], default format StringUtf.

Usable formats: HexBytes, String8, StringUtf, StringUtfBom, StringXml, StringJson.

pub const ZStringChar16: FieldEncoding

zero-terminated uint16[], default format StringUtf.

Usable formats: HexBytes, StringUtf, StringUtfBom, StringXml, StringJson.

pub const ZStringChar32: FieldEncoding

zero-terminated uint32[], default format StringUtf.

Usable formats: HexBytes, StringUtf, StringUtfBom, StringXml, StringJson.

pub const StringLength16Char8: FieldEncoding

uint16 Length followed by uint8 Data[Length], default format StringUtf. Used for string and binary data. Also used for nullable fields.

Usable formats: any.

pub const StringLength16Char16: FieldEncoding

uint16 Length followed by uint16 Data[Length], default format StringUtf.

Usable formats: HexBytes, StringUtf, StringUtfBom, StringXml, StringJson.

pub const StringLength16Char32: FieldEncoding

uint16 Length followed by uint32 Data[Length], default format StringUtf.

Usable formats: HexBytes, StringUtf, StringUtfBom, StringXml, StringJson.

pub const BinaryLength16Char8: FieldEncoding

uint16 Length followed by uint8 Data[Length], default format HexBytes. Used for string and binary data. Also used for nullable fields.

Usable formats: any.

pub const ValueSize: FieldEncoding

usize value, default format UnsignedInt. This is an alias for either Value32 or Value64.

Usable formats: UnsignedInt, SignedInt, HexInt, Time, Float, HexBytes.

pub const ValueMask: u8 = 31u8

Mask for the kind field.

pub const FlagMask: u8 = 224u8

Mask for the flags.

pub const ArrayFlagMask: u8 = 96u8

Mask for the array flags.

pub const CArrayFlag: u8 = 32u8

Constant-length array: 16-bit element count in metadata (count must not be 0).

pub const VArrayFlag: u8 = 64u8

Variable-length array: 16-bit element count in payload (count may be 0).

pub const ChainFlag: u8 = 128u8

A FieldFormat byte follows the FieldEncoding byte.

pub const fn from_int(value: u8) -> FieldEncoding

Returns a FieldEncoding with the specified value.

pub const fn as_int(self) -> u8

Returns the numeric value corresponding to this FieldEncoding value.

pub const fn without_flags(self) -> FieldEncoding

Returns the encoding without any flags (encoding & ValueMask).

pub const fn with_flags(self, flags: u8) -> FieldEncoding

Returns the encoding or’ed with the specified flags (encoding | flags).

pub const fn without_chain_flag(self) -> FieldEncoding

Returns the encoding without the chain flags (encoding & !ChainFlag).

pub const fn array_flags(self) -> u8

Returns the array flags of the encoding (encoding & (CArrayFlag | VArrayFlag)).

pub const fn is_array(self) -> bool

Returns true if any array flag is present (constant-length or variable-length array).

pub const fn is_constant_length_array(self) -> bool

Returns true if CArrayFlag is present (constant-length array).

pub const fn is_variable_length_array(self) -> bool

Returns true if VArrayFlag is present (variable-length array).

pub const fn has_chain_flag(self) -> bool

Returns true if ChainFlag is present (format byte is present in event).

Trait Implementations

impl Clone for FieldEncoding

fn clone(&self) -> FieldEncoding

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FieldEncoding

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Default for FieldEncoding

fn default() -> FieldEncoding

Returns the “default value” for a type.

impl Display for FieldEncoding

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl From<u8> for FieldEncoding

fn from(val: u8) -> FieldEncoding

Converts to this type from the input type.

impl Hash for FieldEncoding

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for FieldEncoding

fn cmp(&self, other: &FieldEncoding) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for FieldEncoding

fn eq(&self, other: &FieldEncoding) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for FieldEncoding

fn partial_cmp(&self, other: &FieldEncoding) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for FieldEncoding

impl Eq for FieldEncoding

impl StructuralPartialEq for FieldEncoding