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R/utils.R
In servr: A Simple HTTP Server to Serve Static Files or Dynamic Documents
Defines functions
browse_last
browse
read_raw
file_size
paste2
decode_path
port_available
random_port
serve_example
build_watcher
daemon_list
daemon_stop
daemon_hint
guess_type
rscript
pkg_file
get_browser
is_rstudio
escape_html
html_doc
fileinfo_table
Documented in
browse_last
daemon_list
daemon_stop
random_port
serve_example
#' @import stats utils
#' @importFrom xfun in_dir
servrEnv = new.env(parent = emptyenv())
# turn file.info() to an HTML table
fileinfo_table = function(info) {
info = info[order(info$isdir, decreasing = TRUE), ]
d = info$isdir; i = !is.na(d)
# files/dirs
x1 = paste(basename(rownames(info)), ifelse(d & i, '/', ''), sep = '')
x1 = escape_html(x1)
x1[i] = sprintf('<a href="%s">%s</a>', x1[i], x1[i])
# size
x2 = paste(format(info$size, scientific = FALSE, big.mark = ','), 'B')
x2[is.na(info$size) | d] = ''
# date modified
x3 = as.character(info$mtime)
x3[is.na(x3)] = ''
c('<table>',
'<thead><tr>',
sprintf('<th>%s</th>', c('Name', 'Size', 'Date Modified')),
'</tr></thead>',
apply(cbind(
'<tr>',
sprintf('<td>%s</td>', x1),
sprintf('<td align="right">%s</td>', x2),
sprintf('<td>%s</td>', x3),
'</tr>'), 1, paste, collapse = ''),
'</table>')
}
# make an HTML document from body and title
html_doc = function(body, title = NULL) {
c('<!DOCTYPE html>', '<html>',
'<head>', sprintf('<title>%s</title>', title), '</head>',
'<body>', body, '</body>', '</html>')
}
# escape special HTML chars (copied from highr)
escape_html = function(x) {
x = gsub('&', '&', x)
x = gsub('<', '<', x)
x = gsub('>', '>', x)
x = gsub('"', '"', x)
x
}
is_rstudio = function() {
requireNamespace('rstudioapi', quietly = TRUE) && rstudioapi::isAvailable()
}
# use the RStudio viewer if possible
get_browser = function() {
if (is_rstudio()) rstudioapi::viewer else getOption('browser')
}
pkg_file = function(...) {
system.file('resources', ..., package = 'servr', mustWork = TRUE)
}
rscript = function(code, input) {
if (system2(file.path(R.home('bin'), 'Rscript'), code, stdout = NULL) != 0)
stop('Failed to compile ', input, call. = FALSE)
}
# use the output from the system utility mimetype if available
guess_type = function(path) {
mimetype = function(...) {
system2('mimetype', c('-b', shQuote(path)), ...)
}
if (Sys.which('mimetype') == '' || mimetype(stdout = NULL) != 0)
return(mime::guess_type(path))
mimetype(stdout = TRUE)
}
servrEnv$daemon_list = list()
# a hint on how to stop the daemonized server
daemon_hint = function(server) {
if (!interactive()) return(invisible(server))
i = length(servrEnv$daemon_list) + 1
servrEnv$daemon_list[[i]] = server
message('To stop the server, run servr::daemon_stop(', i, ') or restart your R session')
invisible(server)
}
#' Utilities for daemonized servers
#'
#' \code{daemon_list()} returns IDs of servers, which can be used to stop the
#' daemonized servers.
#' @param which A integer vector of the server IDs; by default, IDs of all
#' existing servers in the current R session obtained from
#' \code{daemon_list()}, i.e., all daemon servers will be stopped by default.
#' @return The function \code{daemon_list()} returns a list of existing server
#' IDs, and \code{daemon_stop()} returns an invisible \code{NULL}.
#' @export
daemon_stop = function(which = daemon_list()) {
for (d in which) {
if (length(s <- servrEnv$daemon_list[[d]]) == 0) next
stopServer(s)
servrEnv$daemon_list[[d]] = list()
}
}
#' @rdname daemon_stop
#' @export
daemon_list = function() {
x = seq_along(servrEnv$daemon_list)
d = integer()
for (i in x) if (length(servrEnv$daemon_list[[i]]) == 0) d = c(d, i)
if (length(d)) x = x[-d]
if (length(x)) x else invisible(x)
}
# watch files with pattern, and rebuild them if necessary
build_watcher = function(pattern, build, dir = getwd()) {
source_info = function() {
file.info(list.files(dir, pattern, recursive = TRUE))[, 'mtime', drop = FALSE]
}
info = source_info()
function(message) {
if (missing(message) || !is.list(message)) return(FALSE)
path = sub('^/', '', message$pathname)
if (!is.character(path) || length(path) != 1 || !file.exists(path))
return(FALSE)
if (!grepl(pattern, path)) return(FALSE)
info2 = source_info()
m1 = info[rownames(info2), 'mtime']
yes = anyNA(m1) || any(info2[, 'mtime'] > m1)
on.exit(info <<- source_info(), add = TRUE)
if (yes) build(path)
yes
}
}
#' A convenience function to serve examples in this package
#'
#' Use server functions to serve built-in examples of this package.
#' @param name the directory name of the example under the directory
#' \code{system.file('examples', package = 'servr')}
#' @param FUN a server function that takes the example path as its first
#' argument, e.g. \code{\link{httd}}, or \code{\link{rmdv1}}
#' @param ... other arguments passed to \code{FUN}
#' @param run whether to run the example (this is mainly for \command{R CMD
#' check} purposes: the examples will not be really served when the R session
#' is not interactive, so they will not block \command{R CMD check})
#' @export
#' @return \code{NULL} if \code{run = FALSE}, otherwise the value returned from
#' \code{FUN()}.
#' @examples # R Markdown v1 or v2
#' servr::serve_example('rmd', servr::rmdv1)
#' servr::serve_example('rmd', servr::rmdv2)
#'
#' # GNU Make
#' servr::serve_example('make1', servr::make)
#' servr::serve_example('make2', servr::make)
serve_example = function(name, FUN, ..., run = interactive()) {
if (!run) return(invisible(NULL))
dir = system.file('examples', name, package = 'servr')
if (!file_test('-d', dir)) stop('The example ', name, ' does not exist')
message('Serving the example ', dir)
FUN(dir, ...)
}
#' Find a random available TCP port
#'
#' Test a series of random TCP ports from 3000 to 8000 (excluding a few that are
#' considered unsafe by Chrome) and return the first available one. A web server
#' can be later started on this port.
#' @param port The preferred port(s).
#' @param n The maximum number of random ports to be tested.
#' @param exclude A vector of port numbers not to be considered.
#' @inheritParams server_config
#' @export
#' @return A port number, or an error if no ports are available.
random_port = function(
port = 4321L, host = getOption('servr.host', '127.0.0.1'), n = 20,
exclude = NULL
) {
# exclude ports considered unsafe by Chrome http://superuser.com/a/188070
ports = sample(setdiff(3000:8000, c(3659, 4045, 5060, 5061, 6000, 6566, 6665:6669, 6697)), n)
ports = setdiff(c(port, ports), exclude)
port = NULL
# when a port has been used on 0.0.0.0, port_available() still returns TRUE
# when the same port is tested on 127.0.0.1, which might be a bug of httpuv;
# so we provide an option to test the availability of a port on 0.0.0.0 when
# we intend to serve a site on 127.0.0.1
test0 = host == '127.0.0.1' && getOption('servr.test.0.0.0.0', TRUE)
for (p in ports) if (port_available(p, host) && (!test0 || port_available(p, '0.0.0.0'))) {
port = p
break
}
if (is.null(port)) stop("Cannot find an available TCP port")
port
}
port_available = function(port, host = getOption('servr.host', '127.0.0.1')) {
tmp = try(startServer(host, port, list(), quiet = TRUE), silent = TRUE)
if (inherits(tmp, 'try-error')) return(FALSE)
stopServer(tmp)
TRUE
}
# decode the requested path
decode_path = function(req) {
path = httpuv::decodeURIComponent(req$PATH_INFO)
Encoding(path) = 'UTF-8'
path
}
paste2 = function(...) paste(c(...), collapse = '\n')
file_size = function(path) file.info(path)[, 'size']
read_raw = function(path) readBin(path, 'raw', file_size(path))
# store the last browsing function, so that we can reopen a page after it has
# been closed in the browser
servrEnv$browse = function(reopen = TRUE) {
message('It seems you have not served any content with servr yet.')
}
#' Reopen the last browsed page
#'
#' If you have launched a page in the browser via \pkg{servr} but closed it
#' later, you may call this function to reopen it.
#' @param open Whether to reopen the lastly browsed page. If \code{FALSE}, the
#' URL of the previously browsed page will be returned.
#' @export
#' @examples servr::browse_last()
browse_last = function(open = TRUE) servrEnv$browse(open)
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servr documentation built on May 3, 2023, 1:18 a.m.
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Defines functions browse_last browse read_raw file_size paste2 decode_path port_available random_port serve_example build_watcher daemon_list daemon_stop daemon_hint guess_type rscript pkg_file get_browser is_rstudio escape_html html_doc fileinfo_table
Documented in browse_last daemon_list daemon_stop random_port serve_example
#' @import stats utils
#' @importFrom xfun in_dir
servrEnv = new.env(parent = emptyenv())
# turn file.info() to an HTML table
fileinfo_table = function(info) {
info = info[order(info$isdir, decreasing = TRUE), ]
d = info$isdir; i = !is.na(d)
# files/dirs
x1 = paste(basename(rownames(info)), ifelse(d & i, '/', ''), sep = '')
x1 = escape_html(x1)
x1[i] = sprintf('<a href="%s">%s</a>', x1[i], x1[i])
# size
x2 = paste(format(info$size, scientific = FALSE, big.mark = ','), 'B')
x2[is.na(info$size) | d] = ''
# date modified
x3 = as.character(info$mtime)
x3[is.na(x3)] = ''
c('<table>',
'<thead><tr>',
sprintf('<th>%s</th>', c('Name', 'Size', 'Date Modified')),
'</tr></thead>',
apply(cbind(
'<tr>',
sprintf('<td>%s</td>', x1),
sprintf('<td align="right">%s</td>', x2),
sprintf('<td>%s</td>', x3),
'</tr>'), 1, paste, collapse = ''),
'</table>')
}
# make an HTML document from body and title
html_doc = function(body, title = NULL) {
c('<!DOCTYPE html>', '<html>',
'<head>', sprintf('<title>%s</title>', title), '</head>',
'<body>', body, '</body>', '</html>')
}
# escape special HTML chars (copied from highr)
escape_html = function(x) {
x = gsub('&', '&', x)
x = gsub('<', '<', x)
x = gsub('>', '>', x)
x = gsub('"', '"', x)
x
}
is_rstudio = function() {
requireNamespace('rstudioapi', quietly = TRUE) && rstudioapi::isAvailable()
}
# use the RStudio viewer if possible
get_browser = function() {
if (is_rstudio()) rstudioapi::viewer else getOption('browser')
}
pkg_file = function(...) {
system.file('resources', ..., package = 'servr', mustWork = TRUE)
}
rscript = function(code, input) {
if (system2(file.path(R.home('bin'), 'Rscript'), code, stdout = NULL) != 0)
stop('Failed to compile ', input, call. = FALSE)
}
# use the output from the system utility mimetype if available
guess_type = function(path) {
mimetype = function(...) {
system2('mimetype', c('-b', shQuote(path)), ...)
}
if (Sys.which('mimetype') == '' || mimetype(stdout = NULL) != 0)
return(mime::guess_type(path))
mimetype(stdout = TRUE)
}
servrEnv$daemon_list = list()
# a hint on how to stop the daemonized server
daemon_hint = function(server) {
if (!interactive()) return(invisible(server))
i = length(servrEnv$daemon_list) + 1
servrEnv$daemon_list[[i]] = server
message('To stop the server, run servr::daemon_stop(', i, ') or restart your R session')
invisible(server)
}
#' Utilities for daemonized servers
#'
#' \code{daemon_list()} returns IDs of servers, which can be used to stop the
#' daemonized servers.
#' @param which A integer vector of the server IDs; by default, IDs of all
#' existing servers in the current R session obtained from
#' \code{daemon_list()}, i.e., all daemon servers will be stopped by default.
#' @return The function \code{daemon_list()} returns a list of existing server
#' IDs, and \code{daemon_stop()} returns an invisible \code{NULL}.
#' @export
daemon_stop = function(which = daemon_list()) {
for (d in which) {
if (length(s <- servrEnv$daemon_list[[d]]) == 0) next
stopServer(s)
servrEnv$daemon_list[[d]] = list()
}
}
#' @rdname daemon_stop
#' @export
daemon_list = function() {
x = seq_along(servrEnv$daemon_list)
d = integer()
for (i in x) if (length(servrEnv$daemon_list[[i]]) == 0) d = c(d, i)
if (length(d)) x = x[-d]
if (length(x)) x else invisible(x)
}
# watch files with pattern, and rebuild them if necessary
build_watcher = function(pattern, build, dir = getwd()) {
source_info = function() {
file.info(list.files(dir, pattern, recursive = TRUE))[, 'mtime', drop = FALSE]
}
info = source_info()
function(message) {
if (missing(message) || !is.list(message)) return(FALSE)
path = sub('^/', '', message$pathname)
if (!is.character(path) || length(path) != 1 || !file.exists(path))
return(FALSE)
if (!grepl(pattern, path)) return(FALSE)
info2 = source_info()
m1 = info[rownames(info2), 'mtime']
yes = anyNA(m1) || any(info2[, 'mtime'] > m1)
on.exit(info <<- source_info(), add = TRUE)
if (yes) build(path)
yes
}
}
#' A convenience function to serve examples in this package
#'
#' Use server functions to serve built-in examples of this package.
#' @param name the directory name of the example under the directory
#' \code{system.file('examples', package = 'servr')}
#' @param FUN a server function that takes the example path as its first
#' argument, e.g. \code{\link{httd}}, or \code{\link{rmdv1}}
#' @param ... other arguments passed to \code{FUN}
#' @param run whether to run the example (this is mainly for \command{R CMD
#' check} purposes: the examples will not be really served when the R session
#' is not interactive, so they will not block \command{R CMD check})
#' @export
#' @return \code{NULL} if \code{run = FALSE}, otherwise the value returned from
#' \code{FUN()}.
#' @examples # R Markdown v1 or v2
#' servr::serve_example('rmd', servr::rmdv1)
#' servr::serve_example('rmd', servr::rmdv2)
#'
#' # GNU Make
#' servr::serve_example('make1', servr::make)
#' servr::serve_example('make2', servr::make)
serve_example = function(name, FUN, ..., run = interactive()) {
if (!run) return(invisible(NULL))
dir = system.file('examples', name, package = 'servr')
if (!file_test('-d', dir)) stop('The example ', name, ' does not exist')
message('Serving the example ', dir)
FUN(dir, ...)
}
#' Find a random available TCP port
#'
#' Test a series of random TCP ports from 3000 to 8000 (excluding a few that are
#' considered unsafe by Chrome) and return the first available one. A web server
#' can be later started on this port.
#' @param port The preferred port(s).
#' @param n The maximum number of random ports to be tested.
#' @param exclude A vector of port numbers not to be considered.
#' @inheritParams server_config
#' @export
#' @return A port number, or an error if no ports are available.
random_port = function(
port = 4321L, host = getOption('servr.host', '127.0.0.1'), n = 20,
exclude = NULL
) {
# exclude ports considered unsafe by Chrome http://superuser.com/a/188070
ports = sample(setdiff(3000:8000, c(3659, 4045, 5060, 5061, 6000, 6566, 6665:6669, 6697)), n)
ports = setdiff(c(port, ports), exclude)
port = NULL
# when a port has been used on 0.0.0.0, port_available() still returns TRUE
# when the same port is tested on 127.0.0.1, which might be a bug of httpuv;
# so we provide an option to test the availability of a port on 0.0.0.0 when
# we intend to serve a site on 127.0.0.1
test0 = host == '127.0.0.1' && getOption('servr.test.0.0.0.0', TRUE)
for (p in ports) if (port_available(p, host) && (!test0 || port_available(p, '0.0.0.0'))) {
port = p
break
}
if (is.null(port)) stop("Cannot find an available TCP port")
port
}
port_available = function(port, host = getOption('servr.host', '127.0.0.1')) {
tmp = try(startServer(host, port, list(), quiet = TRUE), silent = TRUE)
if (inherits(tmp, 'try-error')) return(FALSE)
stopServer(tmp)
TRUE
}
# decode the requested path
decode_path = function(req) {
path = httpuv::decodeURIComponent(req$PATH_INFO)
Encoding(path) = 'UTF-8'
path
}
paste2 = function(...) paste(c(...), collapse = '\n')
file_size = function(path) file.info(path)[, 'size']
read_raw = function(path) readBin(path, 'raw', file_size(path))
# store the last browsing function, so that we can reopen a page after it has
# been closed in the browser
servrEnv$browse = function(reopen = TRUE) {
message('It seems you have not served any content with servr yet.')
}
#' Reopen the last browsed page
#'
#' If you have launched a page in the browser via \pkg{servr} but closed it
#' later, you may call this function to reopen it.
#' @param open Whether to reopen the lastly browsed page. If \code{FALSE}, the
#' URL of the previously browsed page will be returned.
#' @export
#' @examples servr::browse_last()
browse_last = function(open = TRUE) servrEnv$browse(open)
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R Package Documentation
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We want your feedback!
Note that we can't provide technical support on individual packages. You should contact the package authors for that.
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