serde_columnar 0.2.0

serde_columnar-0.2.0 has been yanked.

Container

#[columnar] means that some fields (marked by #[columnar(type = "vec"|"map")]) of this structure can be serialized and deserialized by columnar encoding
#[columnar(vec, map)] means the struct can be a row inside [Vec] or [HashMap]
#[columnar(ser, de)] means the struct can be serialized or deserialized or both by columnar encoding

#[columnar(index = 1|2|3...)]: the id of the field; TODO:
#[columnar(type = "vec"|"map")]:
vec means the decorated field T is a container, holds Value and satisfies &T: IntoIter<Item=&Value> T: FromIterator<Value>
map means the decorated field T is a container, holds Value and satisfies &T: IntoIter<Item=(&K, &Value)> T: FromIterator<(K, Value)>
#[columnar(strategy = "Rle"|"BooleanRle"|"DeltaRle")]: You can only choose one from the three
Rle: [columnar::strategy::rle]
BooleanRle
DeltaRle
#[columnar(original_type="u32")]: this attribute is used to tell the columnar encoding the original type of the field, which is used when the field is a number

#[columnar(compress)]: compress the columnar encoded bytes by default settings of Deflate algorithm.
more compress options:
#[columnar(compress(min_size=N))]: compress the columnar encoded bytes when the size of the bytes is larger than N, default N is 256.
#[columnar(compress(level=N))]: compress the columnar encoded bytes by Deflate algorithm with level N, N is in [0, 9], default N is 6, 0 is no compression, 9 is the best compression. See flate2 for more details.
#[columnar(compress(method="fast"|"best"|"default"))]: compress the columnar encoded bytes by Deflate algorithm with method "fast", "best" or "default", this attribute is equivalent to #[columnar(compress(level=1|9|6))].
Note: level and method can not be used at the same time.