R/httppipe.R

In richfitz/stevedore: Docker Client

## Basically identical to httppipe but with the docstrings removed
## diff stevedore/R/httppipe.R httppipe/R/httppipe.R

httppipe <- function(path) {
  handle <- httppipe_prepare()$Transporter(path)

  function(method, path, body = NULL, headers = NULL, stream = NULL) {
    if (!is.null(stream)) {
      stop("streaming connections not yet implemented")
    }

    url <- paste0(handle$base_url, path)
    headers <- as.list(headers) # list required for python marshalling

    if (!is.null(body)) {
      assert_raw(body)
    }

    res <- handle$simple_request(method, url, headers, body)

    res$headers <- charToRaw(res$headers)
    if (res$is_binary) {
      res$content <- as.raw(as.integer(res$content))
    } else {
      res$content <- charToRaw(res$content)
    }
    res$is_binary <- NULL
    res
  }
}


httppipe_available <- function(verbose = FALSE) {
  do_httppipe_available(verbose, httppipe_prepare)
}


do_httppipe_available <- function(verbose, prepare) {
  e <- tryCatch(prepare(), error = identity)
  err <- inherits(e, "error")
  if (verbose && err) {
    message(sprintf("Failed to load httppipe with error message:\n  %s",
                    e$message))
  }
  !err
}


httppipe_prepare <- function() {
  loadNamespace("reticulate")
  if (!is.null(.stevedore$httppipe)) {
    return(.stevedore$httppipe)
  }

  path_py <- system.file("py", package = "stevedore", mustWork = TRUE)

  python_set_version("docker")
  python_update_search_path(path_py)
  .stevedore$httppipe <- reticulate::import("httppipe")
  .stevedore$httppipe
}


python_locate_version <- function(module) {
  if (module %in% names(.stevedore$python)) {
    cfg <- .stevedore$python[[module]]
  } else {
    cfg <- reticulate::py_discover_config(module)
    .stevedore$python[[module]] <- cfg
  }
  if (is.null(cfg$required_module_path)) {
    stop(sprintf("Did not find required python module '%s'", module),
         call. = FALSE)
  }
  cfg$python
}


python_set_version <- function(module) {
  reticulate::use_python(python_locate_version("docker"), TRUE)
}


python_update_search_path <- function(path) {
  reticulate::py_run_string("import sys")
  search <- reticulate::py_eval("sys.path")
  if (!(path %in% search)) {
    reticulate::py_run_string(sprintf("sys.path.insert(1, '%s')", path))
  }
}