read_RAST(), write_RAST(): drop GDAL-driver use (revert e1f026d, a06e782

, 4389249) *

In the course of this fiddling with mapsets, it was seen (by accident) that the mapset
region settings are not respected by the GDAL driver.

This only affects raster.

This is a no-go for the GDAL-GRASS raster driver as long as it doesn't expose an option to
respect the mapset's current region, or at least to set a region.

A feature request has been made at the driver's repo
(OSGeo/gdal-grass#49). As long as it's not implemented, we
cannot consider using the driver for rasters since results with and without using the
driver must of course have the same extent and resolution.

R/rast_link.R

@@ -4,7 +4,7 @@
 
 read_RAST <- function(
     vname, cat = NULL, NODATA = NULL, return_format = "terra",
-    use_gdal_grass_driver = TRUE, close_OK = return_format == "SGDF",
+    close_OK = return_format == "SGDF",
     flags = NULL, Sys_ignore.stdout = FALSE,
     ignore.stderr = get.ignore.stderrOption()) {
   if (!is.null(cat)) {
@@ -19,7 +19,6 @@ read_RAST <- function(
     openedConns <- as.integer(row.names(showConnections()))
   }
   stopifnot(is.logical(ignore.stderr), !is.na(ignore.stderr))
-  stopifnot(is.logical(use_gdal_grass_driver), !is.na(use_gdal_grass_driver))
 
   if (!is.null(NODATA)) {
     if (any(!is.finite(NODATA)) || any(!is.numeric(NODATA))) {
@@ -53,23 +52,20 @@ read_RAST <- function(
     if (!(requireNamespace("terra", quietly = TRUE))) {
       stop("terra required for SpatRaster output")
     }
-    has_grassraster_drv <- gdal_has_grassraster_driver()
-    if (!has_grassraster_drv || !use_gdal_grass_driver) {
-      drv <- "RRASTER"
-      fxt <- ".grd"
-      ro <- FALSE
-      o <- execGRASS("r.out.gdal", flags = "l", intern = TRUE)
-      oo <- grep("RRASTER", o)
-      if (length(oo) == 0L) ro <- TRUE
-      if (!ro) {
-        RR <- o[oo]
-        RRs <- strsplit(RR, " ")[[1]]
-        if (length(grep("\\(rw", RRs)) == 0L) ro <- TRUE
-      }
-      if (ro) {
-        drv <- "GTiff"
-        fxt <- ".tif"
-      }
+    drv <- "RRASTER"
+    fxt <- ".grd"
+    ro <- FALSE
+    o <- execGRASS("r.out.gdal", flags = "l", intern = TRUE)
+    oo <- grep("RRASTER", o)
+    if (length(oo) == 0L) ro <- TRUE
+    if (!ro) {
+      RR <- o[oo]
+      RRs <- strsplit(RR, " ")[[1]]
+      if (length(grep("\\(rw", RRs)) == 0L) ro <- TRUE
+    }
+    if (ro) {
+      drv <- "GTiff"
+      fxt <- ".tif"
     }
     reslist <- vector(mode = "list", length = length(vname))
     names(reslist) <- gsub("@", "_", vname)
@@ -174,31 +170,24 @@ read_RAST <- function(
       } else {
         NODATAi <- NODATA[i]
       }
-      if (has_grassraster_drv && use_gdal_grass_driver) {
-        args <- list(name = vca[1], type = "raster")
-        if (length(vca) == 2L) args <- c(args, mapset = vca[2])
-        tmplist[[i]] <- do.call(generate_header_path, args)
+      tmplist[[i]] <- tempfile(fileext = fxt)
+      if (is.null(flags)) flags <- c("overwrite", "c", "m")
+      if (!is.null(cat) && cat[i]) flags <- c(flags, "t")
+      if (is.null(typei)) {
+        execGRASS("r.out.gdal",
+                  input = vname[i], output = tmplist[[i]],
+                  format = drv, nodata = NODATAi, flags = flags,
+                  ignore.stderr = ignore.stderr,
+                  Sys_ignore.stdout = Sys_ignore.stdout
+        )
       } else {
-        tmplist[[i]] <- tempfile(fileext = fxt)
-        if (is.null(flags)) flags <- c("overwrite", "c", "m")
-        if (!is.null(cat) && cat[i]) flags <- c(flags, "t")
-        if (is.null(typei)) {
-          execGRASS("r.out.gdal",
-                    input = vname[i], output = tmplist[[i]],
-                    format = drv, nodata = NODATAi, flags = flags,
-                    ignore.stderr = ignore.stderr,
-                    Sys_ignore.stdout = Sys_ignore.stdout
-          )
-        } else {
-          execGRASS("r.out.gdal",
-                    input = vname[i], output = tmplist[[i]],
-                    format = drv, nodata = NODATAi, type = typei, flags = flags,
-                    ignore.stderr = ignore.stderr,
-                    Sys_ignore.stdout = Sys_ignore.stdout
-          )
-        }
+        execGRASS("r.out.gdal",
+                  input = vname[i], output = tmplist[[i]],
+                  format = drv, nodata = NODATAi, type = typei, flags = flags,
+                  ignore.stderr = ignore.stderr,
+                  Sys_ignore.stdout = Sys_ignore.stdout
+        )
       }
-      # message("Reading ", tmplist[[i]])
       reslist[[i]] <- getMethod("rast", "character")(tmplist[[i]])
     }
     resa <- getMethod("rast", "list")(reslist)
@@ -578,18 +567,6 @@ write_RAST <- function(
     } else {
       tf <- ""
     }
-    # exit when the source is a GRASS database layer already:
-    if (grepl("[/\\\\]cellhd[/\\\\][^/\\\\]+$", tf)) {
-      grass_layername <- regmatches(
-        tf,
-        regexpr("(?<=[/\\\\]cellhd[/\\\\])[^/\\\\]+$", tf, perl = TRUE)
-      )
-      stop(
-        "This SpatRaster already links to the following raster layer in the ",
-        "GRASS GIS database: ",
-        grass_layername
-      )
-    }
     if (!file.exists(tf)) {
       drv <- "RRASTER"
       fxt <- ".grd"

man/readRAST.Rd

@@ -11,7 +11,7 @@ Read GRASS raster files from GRASS into R \pkg{terra} \code{"SpatRaster"} or \pk
 
 \usage{
 read_RAST(vname, cat=NULL, NODATA=NULL,
- return_format="terra", use_gdal_grass_driver = TRUE, close_OK=return_format=="SGDF",
+ return_format="terra", close_OK=return_format=="SGDF",
  flags=NULL, Sys_ignore.stdout = FALSE, ignore.stderr=get.ignore.stderrOption())
 write_RAST(x, vname, zcol = 1, NODATA=NULL, flags=NULL,
  ignore.stderr = get.ignore.stderrOption(), overwrite=FALSE, verbose=TRUE)
@@ -21,7 +21,6 @@ write_RAST(x, vname, zcol = 1, NODATA=NULL, flags=NULL,
   \item{vname}{A vector of GRASS raster file names in mapsets in the current search path, as set by \dQuote{g.mapsets}; the file names may be given as fully-qualified map names using \dQuote{name@mapset}, in which case only the mapset given in the full path will be searched for the existence of the raster; if more than one raster with the same name is found in mapsets in the current search path, an error will occur, in which case the user should give the fully-qualified map name. If the fully-qualified name is used, \code{@} will be replaced by underscore in the output object.}
   \item{cat}{default NULL; if not NULL, must be a logical vector matching vname, stating which (CELL) rasters to return as factor}
   \item{return_format}{default \code{"terra"}, optionally \code{"SGDF"}}
-  \item{use_gdal_grass_driver}{Default \code{TRUE}. The \href{https://github.com/OSGeo/gdal-grass}{standalone GDAL-GRASS driver} for the raster format will be used if \code{return_format} is \code{"terra"} and if the driver is installed. The advantage is that no intermediate file(s) need to be written from GRASS GIS and subsequently read into R; instead the raster dataset(s) are read directly from the GRASS GIS database. Please read the \strong{Note} further below!}
   \item{Sys_ignore.stdout}{Passed to \code{system}.}
   \item{ignore.stderr}{default taking the value set by \code{set.ignore.stderrOption}; can be set to TRUE to silence \code{system()} output to standard error; does not apply on Windows platforms}
   \item{close_OK}{default TRUE - clean up possible open connections used for reading metadata; may be set to FALSE to avoid the side-effect of other user-opened connections being broken}
@@ -35,10 +34,6 @@ write_RAST(x, vname, zcol = 1, NODATA=NULL, flags=NULL,
 
 \value{\code{read_RAST} by default returns a SpatRaster object, but may return a legacy SpatialGridDataFrame object if \code{return_format="SGDF"}. \code{write_RAST} silently returns the object being written to GRASS.}
 
-\note{
-Be aware that the GDAL-GRASS driver may currently return incomplete metadata about the coordinate reference system, e.g. it may miss the EPSG code.
-}
-
 \author{Roger S. Bivand, e-mail: \email{Roger.Bivand@nhh.no}}
 
 \examples{
@@ -76,11 +71,9 @@ if (run) {
   inMemory(v1)
 }
 if (run) {
-  try({
-    write_RAST(v1, "landuse1", flags=c("o", "overwrite"))
-    execGRASS("r.stats", flags="c", input="landuse1")
-    execGRASS("g.remove", flags="f", name="landuse1", type="raster")
-  })
+  write_RAST(v1, "landuse1", flags=c("o", "overwrite"))
+  execGRASS("r.stats", flags="c", input="landuse1")
+  execGRASS("g.remove", flags="f", name="landuse1", type="raster")
 }
 Sys.setenv("_SP_EVOLUTION_STATUS_"="2")
 run <- run && require("sp", quietly=TRUE)
@@ -108,17 +101,10 @@ if (run) {
 }
 if (run) {
   print(system.time(sqdem <- read_RAST(c("sqdemSP", "elevation"),
-                                       return_format="terra",
-                                       use_gdal_grass_driver = FALSE)))
-}
-# install the GDAL-GRASS driver to achieve higher speed:
-if (run) {
-  print(system.time(sqdem <- read_RAST(c("sqdemSP", "elevation"),
-                                       return_format="terra",
-                                       use_gdal_grass_driver = TRUE)))
+    return_format="terra")))
 }
 if (run) {
-  names(sqdem)
+names(sqdem)
 }
 if (run) {
   sqdem1 <- read_RAST(c("sqdemSP@RGRASS_EXAMPLES", "elevation@PERMANENT"))