Package 'protolite'

Geobuf

Description

The geobuf format is an optimized binary format for storing geojson data with protocol buffers. These functions are compatible with the geobuf2json and json2geobuf utilities from the geobuf npm package.

Usage

read_geobuf(x, as_data_frame = TRUE)

geobuf2json(x, pretty = FALSE)

json2geobuf(json, decimals = 6)

Arguments

x	file path or raw vector with the serialized geobuf.proto message
as_data_frame	simplify geojson data into data frames
pretty	indent json, see jsonlite::toJSON
json	a text string with geojson data
decimals	how many decimals (digits behind the dot) to store for numbers

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Mapbox Vector Tiles

Description

Read Mapbox vector-tile (mvt) files and returns the list of layers.

Usage

read_mvt_data(data, as_latlon = TRUE, zxy = NULL)

read_mvt_sf(data, crs = 4326, zxy = NULL)

Arguments

data	url, path or raw vector with the mvt data
as_latlon	return the data as lat/lon instead of raw EPSG:3857 positions
zxy	vector of length 3 with respectively z (zoom), x (column) and y (row). For file/url in the standard ⁠../{z}/{x}/{y}.mvt⁠ format, these are automatically inferred from the input path.
crs	desired output coordinate system (passed to sf::st_transform). Note that mvt input is always by definition 3857.

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Serialize to Protocol Buffers

Description

Serializes R objects to a general purpose protobuf message. It uses the same rexp.proto descriptor and mapping between R objects and protobuf messages as RHIPE and the RProtoBuf package.

Usage

serialize_pb(object, connection = NULL, skip_native = FALSE)

unserialize_pb(msg)

Arguments

object	an R object to serialize
connection	a connection, file, or NULL for a raw vector
skip_native	do not serialize 'native' (non-data) R objects. Setting to TRUE will only serialize data types (numeric, boolean, string, raw, list). The default behavior is to fall back on base R serialize for non-data objects.
msg	raw vector with the serialized rexp.proto message

Details

The serialize_pb and unserialize_pb reimplement the identically named functions from the RProtoBuf package in pure C++. This makes the function faster and simpler, but the output should be identical.

Examples

# Serialize and unserialize an object
buf <- serialize_pb(iris)
out <- unserialize_pb(buf)
stopifnot(identical(iris, out))

## Not run:  #Fully compatible with RProtoBuf
buf <- RProtoBuf::serialize_pb(iris, NULL)
out <- protolite::unserialize_pb(buf)
stopifnot(identical(iris, out))

# Other way around
buf <- protolite::serialize_pb(mtcars, NULL)
out <- RProtoBuf::unserialize_pb(buf)
stopifnot(identical(mtcars, out))

## End(Not run)

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