fix segfault and add two function for handle and booster

R-package/R/predict.xgb.Booster.R

@@ -36,12 +36,7 @@ setMethod("predict", signature = "xgb.Booster",
   if (class(object) != "xgb.Booster"){
     stop("predict: model in prediction must be of class xgb.Booster")
   } else {
-    if (is.null(object$handle)) {
-      object$handle <- xgb.load(object$raw)
-    } else {
-      if (is.null(object$raw))
-        object$raw <- xgb.save.raw(object$handle)
-    }
+    object <- xgb.Booster.check(object, saveraw = FALSE)
   }
   if (class(newdata) != "xgb.DMatrix") {
     if (is.null(missing)) {

R-package/R/predict.xgb.Booster.handle.R

@@ -6,9 +6,9 @@ setMethod("predict", signature = "xgb.Booster.handle",
     stop("predict: model in prediction must be of class xgb.Booster.handle")
   }
   
-  bst <- list(handle = object,raw = NULL)
-  class(bst) <- 'xgb.Booster'
-  bst$raw <- xgb.save.raw(bst$handle)
+  bst <- xgb.handleToBooster(object)
+  # Avoid save a handle without update
+  # bst$raw <- xgb.save.raw(object)
   
   ret = predict(bst, ...)
   return(ret)

R-package/R/utils.R

@@ -68,6 +68,26 @@ xgb.Booster <- function(params = list(), cachelist = list(), modelfile = NULL) {
   return(structure(handle, class = "xgb.Booster.handle"))
 }
 
+# convert xgb.Booster.handle to xgb.Booster
+xgb.handleToBooster <- function(handle)
+{
+  bst <- list(handle = handle, raw = NULL)
+  class(bst) <- "xgb.Booster"
+  return(bst)
+}
+
+# Check whether an xgb.Booster object is complete
+xgb.Booster.check <- function(bst, saveraw = TRUE)
+{
+  if (is.null(bst$handle)) {
+    bst$handle <- xgb.load(bst$raw)
+  } else {
+    if (is.null(bst$raw) && saveraw)
+      bst$raw <- xgb.save.raw(bst$handle)
+  }
+  return(bst)
+}
+
 ## ----the following are low level iteratively function, not needed if
 ## you do not want to use them ---------------------------------------
 # get dmatrix from data, label

R-package/R/xgb.dump.R

@@ -41,12 +41,7 @@ xgb.dump <- function(model = NULL, fname = NULL, fmap = "", with.stats=FALSE) {
   if (class(model) != "xgb.Booster") {
     stop("model: argument must be type xgb.Booster")
   } else {
-    if (is.null(model$handle)) {
-      model$handle <- xgb.load(model$raw)
-    } else {
-      if (is.null(model$raw))
-        model$raw <- xgb.save.raw(model$handle)
-    }
+    model <- xgb.Booster.check(model)
   }
   if (!(class(fname) %in% c("character", "NULL") && length(fname) <= 1)) {
     stop("fname: argument must be type character (when provided)")

R-package/R/xgb.load.R

@@ -20,9 +20,8 @@ xgb.load <- function(modelfile) {
   if (is.null(modelfile)) 
     stop("xgb.load: modelfile cannot be NULL")
   
-  bst <- list(handle = NULL,raw = NULL)
-  class(bst) <- 'xgb.Booster'
-  bst$handle <- xgb.Booster(modelfile = modelfile)
-  bst$raw <- xgb.save.raw(bst$handle)
+  handle <- xgb.Booster(modelfile = modelfile)
+  bst <- xgb.handleToBooster(handle)
+  bst <- xgb.Booster.check(bst)
   return(bst)
 } 

R-package/R/xgb.save.R

@@ -22,9 +22,7 @@ xgb.save <- function(model, fname) {
     stop("xgb.save: fname must be character")
   }
   if (class(model) == "xgb.Booster") {
-    if (is.null(model$handle)) {
-      model$handle <- xgb.load(model$raw)
-    }
+    model <- xgb.Booster.check(model)
     .Call("XGBoosterSaveModel_R", model$handle, fname, PACKAGE = "xgboost")
     return(TRUE)
   }

R-package/R/xgb.train.R

@@ -86,9 +86,8 @@ xgb.train <- function(params=list(), data, nrounds, watchlist = list(),
   }
   params = append(params, list(...))
   
-  bst <- list(handle = NULL,raw = NULL)
-  class(bst) <- 'xgb.Booster'
-  bst$handle <- xgb.Booster(params, append(watchlist, dtrain))
+  handle <- xgb.Booster(params, append(watchlist, dtrain))
+  bst <- xgb.handleToBooster(handle)
   for (i in 1:nrounds) {
     succ <- xgb.iter.update(bst$handle, dtrain, i - 1, obj)
     if (length(watchlist) != 0) {
@@ -96,6 +95,6 @@ xgb.train <- function(params=list(), data, nrounds, watchlist = list(),
       cat(paste(msg, "\n", sep=""))
     }
   }
-  bst$raw <- xgb.save.raw(bst$handle)
+  bst <- xgb.Booster.check(bst)
   return(bst)
 }