Ensure on disk contents work like in memory.

Closes #44

NAMESPACE

@@ -8,6 +8,7 @@ S3method(c,config)
 S3method(cookies,handle)
 S3method(cookies,response)
 S3method(headers,response)
+S3method(length,path)
 S3method(print,cache_info)
 S3method(print,config)
 S3method(print,handle)

NEWS.md

@@ -1,5 +1,9 @@
 # httr 0.4.0.99
 
+* You can now save response bodies directly to disk by using the `write_disk()`
+  config. This is useful if you want to capture large files that don't fit in
+  memory (#44).
+
 * Typo which broke `set_cookies()` fixed by @hrbrmstr.
 
 * `content(type = "text")` uses `readBin()` instead of `rawToChar()` so

R/content.r

@@ -63,10 +63,16 @@ content <- function(x, as = NULL, type = NULL, encoding = NULL, ...) {
   as <- as %||% parseability(type)
   as <- match.arg(as, c("raw", "text", "parsed"))
 
+  if (is.path(x$content)) {
+    raw <- readBin(x$content, "raw", file.info(x$content)$size)
+  } else {
+    raw <- x$content
+  }
+
   switch(as,
-    raw = x$content,
-    text = parse_text(x$content, type, encoding),
-    parsed = parse_auto(x$content, type, encoding, ...)
+    raw = raw,
+    text = parse_text(raw, type, encoding),
+    parsed = parse_auto(raw, type, encoding, ...)
   )
 }
 

R/response.r

@@ -42,6 +42,10 @@ print.response <- function(x, ..., max.lines = 10, width = getOption("width")) {
   }
 
   cat("  Size: ", bytes(size), "\n", sep = "")
+  if (is.path(x$content)) {
+    cat("<ON DISK> ", x$content)
+    return()
+  }
   if (!is_text(content_type)) {
     cat("<BINARY BODY>\n")
     return()

R/write-function.R

@@ -41,11 +41,17 @@ write_term <- function(x) UseMethod("write_term")
 #' @useDynLib httr writer
 #' @examples
 #' tmp <- tempfile()
-#' r <- GET("https://www.google.com", write_disk(tmp))
+#' r1 <- GET("https://www.google.com", write_disk(tmp))
 #' readLines(tmp)
 #'
 #' # The default
-#' r <- GET("https://www.google.com", write_memory())
+#' r2 <- GET("https://www.google.com", write_memory())
+#'
+#' # Save a very large file
+#' \dontrun{
+#' GET("http://www2.census.gov/acs2011_5yr/pums/csv_pus.zip",
+#'   write_disk("csv_pus.zip"), progress())
+#' }
 write_disk <- function(path, overwrite = FALSE) {
   if (!overwrite && file.exists(path)) {
     stop("Path exists and overrwrite is FALSE", call. = FALSE)
@@ -79,6 +85,9 @@ print.write_disk <- function(x, ...) {
 }
 
 path <- function(x) structure(x, class = "path")
+#' @export
+length.path <- function(x) file.info(x)$size
+is.path <- function(x) inherits(x, "path")
 
 #' @rdname write_disk
 #' @export

man/write_disk.Rd

@@ -21,10 +21,16 @@ than memory, use \code{write_disk()} to save it to a known path.
 }
 \examples{
 tmp <- tempfile()
-r <- GET("https://www.google.com", write_disk(tmp))
+r1 <- GET("https://www.google.com", write_disk(tmp))
 readLines(tmp)
 
 # The default
-r <- GET("https://www.google.com", write_memory())
+r2 <- GET("https://www.google.com", write_memory())
+
+# Save a very large file
+\dontrun{
+GET("http://www2.census.gov/acs2011_5yr/pums/csv_pus.zip",
+  write_disk("csv_pus.zip"), progress())
+}
 }