X-Git-Url: https://gerrit.simantics.org/r/gitweb?a=blobdiff_plain;f=bundles%2Forg.simantics.db.impl%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fimpl%2FTableHeader.java;fp=bundles%2Forg.simantics.db.impl%2Fsrc%2Forg%2Fsimantics%2Fdb%2Fimpl%2FTableHeader.java;h=e0b8548561165359ef82a5048375734a7d4821db;hb=969bd23cab98a79ca9101af33334000879fb60c5;hp=0000000000000000000000000000000000000000;hpb=866dba5cd5a3929bbeae85991796acb212338a08;p=simantics%2Fplatform.git

diff --git a/bundles/org.simantics.db.impl/src/org/simantics/db/impl/TableHeader.java b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/TableHeader.java
new file mode 100644
index 000000000..e0b854856
--- /dev/null
+++ b/bundles/org.simantics.db.impl/src/org/simantics/db/impl/TableHeader.java
@@ -0,0 +1,64 @@
+package org.simantics.db.impl;
+
+public class TableHeader  {
+    public static final int HEADER_SIZE = 4;
+    public static final int EXTRA_SIZE = 4;
+    private final int CAPACITY_INDEX; // Max size of memory than can be used for entries. (Table size without header.)
+    private final int SIZE_INDEX; // Memory used for entries.
+    private final int COUNT_INDEX; // Number of elements.
+    private final int OFFSET_INDEX; // Table offset in containing vector minus zero shift.
+    private final int EXTRA_INDEX; // Extra header fields for clients.
+    private int[] header;
+   TableHeader(int[] header, int headerBase) {
+       this.CAPACITY_INDEX = headerBase++;
+       this.SIZE_INDEX = headerBase++;
+       this.COUNT_INDEX = headerBase++;
+       this.OFFSET_INDEX = headerBase++;
+       this.EXTRA_INDEX = headerBase++;
+       this.header = header;
+       getOffset();
+       getSize();
+       getCapacity();
+   }
+   final int getCapacity() {
+       int ret = header[CAPACITY_INDEX];
+       if(ret < 0) throw new IllegalStateException();
+       return ret;
+   }
+   final void setCapacity(int a) {
+       header[CAPACITY_INDEX] = a;
+   }
+   final int getSize() {
+       int ret = header[SIZE_INDEX];
+       if(ret < 0) throw new IllegalStateException();
+       if(ret > getCapacity()) throw new IllegalStateException();
+       return ret;
+   }
+   final void setSize(int a) {
+       header[SIZE_INDEX] = a;
+   }
+   public final int getCount() {
+       return header[COUNT_INDEX];
+   }
+   final void setCount(int a) {
+       header[COUNT_INDEX] = a;
+   }
+   public final int getOffset() {
+       int ret = header[OFFSET_INDEX];
+       if(ret < -1) throw new IllegalStateException();
+       return ret; 
+   }
+   final void setOffset(int a) {
+       header[OFFSET_INDEX] = a;
+   }
+   final int getExtra(int index) {
+       if (index < 0 || index >= EXTRA_SIZE)
+           throw new IllegalArgumentException();
+       return header[EXTRA_INDEX + index];
+   }
+   final void setExtra(int index, int a) {
+       if (index < 0 || index >= EXTRA_SIZE)
+           throw new IllegalArgumentException();
+       header[EXTRA_INDEX + index] = a;
+   }
+}
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