1 files changed, 128 insertions, 0 deletions
diff --git a/src/recover.c b/src/recover.c
new file mode 100644
index 0000000..2131542
--- /dev/null
+++ b/src/recover.c
@@ -0,0 +1,128 @@
+#include "recover.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h> /* for usleep - to be removed */
+
+// Main algorithm for recover datas
+void recover(slices_evt_t *slicesEvt, char *src, char *dst, char *ddOpts) {
+	slice_t *sliceToRead;
+	address_t firstError=0, median, foundMax=0;
+	int res;
+
+	//sliceToRead=slicesEvt->data->first;
+	sliceToRead=slicesFindLargest(slicesEvt->data, S_UNKNOWN);
+	while (!end) { 
+		// try to recover sliceToRead and split it if read error
+		switch ( tryRecoverUntilError(sliceToRead, &firstError, src, dst, ddOpts) ) {
+			case 0:
+				// slice recovery has been executed without read error
+				sliceToRead->status=S_RECOVERED;
+				break;
+			case EIO:
+				// slice recovery has encountered a readerror
+				res=sliceEvtSplit(slicesEvt, sliceToRead, firstError, S_RECOVERED, S_UNREADABLE, S_UNKNOWN);
+				if (res<1) {
+					//TODO
+					printf("sliceEvtSplit return %d\n", res);
+					exit(5);
+				}
+				break;
+			default:
+				exit(2); //TODO
+		}
+
+		/* Now, search the largest S_UNKNOWN zone
+		 split it in two parts */
+		//sliceToRead=slicesFindLargest(slices, S_UNKNOWN);
+		sliceToRead=slicesFindLargestFast(slicesEvt->data, &foundMax, S_UNKNOWN, foundMax, sliceToRead->next);
+		if ( sliceToRead == NULL ) {
+			// There is nothing more to recover, bailout
+			end=1;
+			continue;
+		}
+			
+
+ 		median=(sliceToRead->begin+sliceToRead->end)/2;
+		res=sliceEvtSplit(slicesEvt, sliceToRead, median, S_UNKNOWN, S_UNKNOWN, S_UNKNOWN);
+		switch (res) {
+			case 1:
+				// No split, try analyse this zone
+				// Should be a slice of length 1
+				break;
+			case 2:
+				/* After splitting an S_UNKNOWN zone in two parts
+				   take the second for further analysis.
+				   We already now that this first one is just preceded by
+				   a read error, and errors are frequently grouped in zones,
+				   so trying to read a sector just after a faulty sector is
+				   most likely a waste of time.
+				*/
+				sliceToRead=sliceToRead->next; 
+				break;
+			case 3:
+				// Internal error of sliceSlpit because this set of parameters prevent split by 3
+				exit(6); // TODO
+				break;
+			case -1:
+				// Memory error
+				exit(5); //TODO
+				break;
+			default:
+				// API error, all necessary cases are already listed
+				exit(7); // TODO
+			}
+	}
+}
+
+// Method tha read source (and clone to dest) until the first read error
+int tryRecoverUntilError(slice_t *sliceToRead, address_t *firstError, char *src, char *dst, char*ddOpts) {
+	//TODO : implement realy that
+	//TODO : bail out hardly if WRITE error (on dest)
+
+//	char ddinvocation[256];
+	int res;
+	address_t seek, count;
+
+	seek=sliceToRead->begin;
+	count=sliceToRead->end - seek + 1;
+//	res=snprintf(ddinvocation, 255, "dd %s %s %s seek=%lld skip=%lld count=%lld", src, dst, ddOpts, seek, seek, count);
+//TODO : listener to put that info on the interface	puts(ddinvocation);
+
+/*
+	// Simulate that we have systematically a read error at first sector
+	*firstError=sliceToRead->begin;
+	res=EIO;
+*/
+/*
+	// Simulate that we have systematically a read error at last sector
+	*firstError=sliceToRead->end;
+	res=EIO;
+*/
+/*
+	// Simulate that we have systematically a read error at first sector
+	// Simulate for each read, tha we have an error just in the middle if read for mor than one sector
+	if ( sliceToRead->begin == sliceToRead->end ) {
+		res=0;
+	} else {
+		*firstError=(sliceToRead->begin + sliceToRead->end)/2;
+		res=EIO;
+	}
+*/
+
+	// Simulate for each read a pseudo random error position and generate some cases of full read without error
+	//address_t error=sliceToRead->begin + rand()%(count);
+	address_t error=sliceToRead->begin + rand()%(count/3);
+	if ( error % 42 == 0 ) {
+		res=0;
+	} else {
+		res=EIO;
+		*firstError=error;
+	}
+
+	// Keep things humanly understandable (to be removed when real reads will be done)
+	//usleep(10000);
+
+	return res;
+}
+