Following discussions on the dev list today, tweak the logic for sizing the HSSFCells array on a HSSFRow to reduce memory over allocation in many use cases (now cribbed from the size of the row, and uses the ArrayList growth metric)

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1095229 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Nick Burch 2011-04-19 22:26:46 +00:00
parent de892d4666
commit 6d6c2fc68f
2 changed files with 11 additions and 3 deletions

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@ -34,6 +34,7 @@
<changes> <changes>
<release version="3.8-beta3" date="2011-??-??"> <release version="3.8-beta3" date="2011-??-??">
<action dev="poi-developers" type="fix">Tweak the logic for sizing the HSSFCells array on a HSSFRow to reduce memory over allocation in many use cases</action>
<action dev="poi-developers" type="add">49765 - Support for adding a picture to a XSSFRun</action> <action dev="poi-developers" type="add">49765 - Support for adding a picture to a XSSFRun</action>
<action dev="poi-developers" type="fix">Rename/Move xssf.model.Table to xssf.usermodel.XSSFTable as it now has usermodel-like features</action> <action dev="poi-developers" type="fix">Rename/Move xssf.model.Table to xssf.usermodel.XSSFTable as it now has usermodel-like features</action>
<action dev="poi-developers" type="fix">51061 - Correct target URI for new XSSF Tables</action> <action dev="poi-developers" type="fix">51061 - Correct target URI for new XSSF Tables</action>

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@ -41,7 +41,7 @@ public final class HSSFRow implements Row {
public final static int INITIAL_CAPACITY = 5; public final static int INITIAL_CAPACITY = 5;
private int rowNum; private int rowNum;
private HSSFCell[] cells=new HSSFCell[INITIAL_CAPACITY]; private HSSFCell[] cells;
/** /**
* reference to low level representation * reference to low level representation
@ -84,6 +84,12 @@ public final class HSSFRow implements Row {
this.sheet = sheet; this.sheet = sheet;
row = record; row = record;
setRowNum(record.getRowNumber()); setRowNum(record.getRowNumber());
// Size the initial cell list such that a read only case won't waste
// lots of memory, and a create/read followed by adding new cells can
// add a bit without needing a resize
cells = new HSSFCell[record.getLastCol()+INITIAL_CAPACITY];
// Don't trust colIx boundaries as read by other apps // Don't trust colIx boundaries as read by other apps
// set the RowRecord empty for the moment // set the RowRecord empty for the moment
record.setEmpty(); record.setEmpty();
@ -300,9 +306,10 @@ public final class HSSFRow implements Row {
// re-allocate cells array as required. // re-allocate cells array as required.
if(column>=cells.length) { if(column>=cells.length) {
HSSFCell[] oldCells=cells; HSSFCell[] oldCells=cells;
int newSize=oldCells.length*2; // New size based on the same logic as ArrayList
int newSize=oldCells.length*3/2+1;
if(newSize<column+1) { if(newSize<column+1) {
newSize=column+1; newSize=column+INITIAL_CAPACITY;
} }
cells=new HSSFCell[newSize]; cells=new HSSFCell[newSize];
System.arraycopy(oldCells,0,cells,0,oldCells.length); System.arraycopy(oldCells,0,cells,0,oldCells.length);