#' @include DataBackend.R
DataBackendRbind = R6Class("DataBackendRbind", inherit = DataBackend, cloneable = FALSE,
public = list(
initialize = function(b1, b2) {
assert_backend(b1)
assert_backend(b2)
pk = b1$primary_key
data_formats = intersect(b1$data_formats, b2$data_formats)
if (length(data_formats) == 0L) {
stopf("There is no common data format for the backends to rbind")
}
if (pk != b2$primary_key) {
stopf("All backends to rbind must have the primary_key '%s'", pk)
}
super$initialize(list(b1 = b1, b2 = b2), pk, "data.table")
},
data = function(rows, cols, data_format = self$data_formats[1L]) {
pk = self$primary_key
qrows = unique(assert_atomic_vector(rows))
qcols = union(assert_names(cols, type = "unique"), pk)
assert_choice(data_format, self$data_formats)
data = private$.data$b2$data(qrows, qcols, data_format = data_format)
if (nrow(data) < length(qrows)) {
qrows = setdiff(rows, data[[pk]])
tmp = private$.data$b1$data(qrows, qcols, data_format = data_format)
data = rbindlist(list(data, tmp), use.names = TRUE, fill = TRUE)
}
# duplicate rows / reorder columns
data[list(rows), intersect(cols, names(data)), nomatch = 0L, on = pk, with = FALSE]
},
head = function(n = 6L) {
rows = head(self$rownames, n)
self$data(rows, cols = self$colnames)
},
distinct = function(rows, cols, na_rm = TRUE) {
cols = intersect(cols, self$colnames)
d1 = private$.data$b1$distinct(rows, cols, na_rm = na_rm)
d2 = private$.data$b2$distinct(rows, cols, na_rm = na_rm)
set_names(map(cols, function(nn) union(d1[[nn]], d2[[nn]])), cols)
},
missings = function(rows, cols) {
cols = intersect(cols, self$colnames)
m1 = as.list(private$.data$b1$missings(rows, cols))
m2 = as.list(private$.data$b2$missings(rows, cols))
set_names(map_int(cols, function(nn) m1[[nn]] %??% 0L + m2[[nn]] %??% 0L), cols)
}
),
active = list(
rownames = function() {
union(private$.data$b1$rownames, private$.data$b2$rownames)
},
colnames = function() {
union(private$.data$b1$colnames, private$.data$b2$colnames)
},
nrow = function() {
uniqueN(c(private$.data$b1$rownames, private$.data$b2$rownames))
},
ncol = function() {
uniqueN(c(private$.data$b1$colnames, private$.data$b2$colnames))
}
),
private = list(
.calculate_hash = function() {
data = private$.data
hash(data$b1$hash, data$b2$hash)
}
)
)
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