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authorLudovic Pouzenc <ludovic@pouzenc.fr>2011-10-09 12:33:48 +0000
committerLudovic Pouzenc <ludovic@pouzenc.fr>2011-10-09 12:33:48 +0000
commit0f2c685db3d3790ce9bdc9598df8dae7d6b67eae (patch)
treea2c2a7f8941e87368ee46163e028c553d1b6bcdf /src/slices.c
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On range tout le code actuel du trunk dans une branche nommée "0.x" et on crée une branche 1.x qui contiendra une nouvelle mouture (re-conception, méta info de packaging...).origin/0.x
git-svn-id: file:///var/svn/2011-ddhardrescue/branches/0.x@29 d3078510-dda0-49f1-841c-895ef4b7ec81
Diffstat (limited to 'src/slices.c')
-rw-r--r--src/slices.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/src/slices.c b/src/slices.c
new file mode 100644
index 0000000..e8f1d49
--- /dev/null
+++ b/src/slices.c
@@ -0,0 +1,282 @@
+#include "slices.h"
+
+#include <string.h>
+#include <stdio.h> /* For perror() */
+
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+slice_t *sliceNew(address_t begin, address_t end, sliceStatus_t status, slice_t *next) {
+ slice_t *s;
+
+ s = malloc(1*sizeof(slice_t));
+ if (s!=NULL) {
+ s->begin=begin;
+ s->end=end;
+ s->status=status;
+ s->next=next;
+ }
+
+ return s;
+}
+
+void sliceDelete(slice_t *s) {
+ free(s);
+}
+
+// Return the numbers of slices after split (3 in the general case, 2 or 1 in particular cases. -1 is memory error)
+int sliceSplit(slices_t *slices, slice_t *initialSlice, address_t splitAt, sliceStatus_t statusBefore, sliceStatus_t statusAt, sliceStatus_t statusAfter) {
+ slice_t *secondSlice, *thirdSlice, *rightSlice;
+ int splitAfterSingularity, splitBeforeSingularity;
+
+ /* Basically, we want to split the slice in 3 :
+ [a;b] shoud be transformed in : [a;splitAt-1], [splitAt;splitAt], [splitAt+1;b]
+ There is exceptions and singularities :
+ * If splitAt is not within [a;b], bail out, no coherent solution
+ * If splitAt==a, the first slice should not exists
+ * If splitAt==b, the last slice shoud not exists
+ * If a==b (and so, ==splitAt), there is nothing to split, just change status
+ But, if statusBefore==statusAt, we don't want an interval [splitAt;splitAt], we want just split in 2.
+ This unwanted interval should be kept merged with the first interval.
+
+ For pratical reasons with pointer mess-up, the first action is to split between the second and the last slice
+ and then between he first and second if needed.
+ */
+ pthread_mutex_lock(&(slices->writeOrConsistentReadMutex));
+
+ if ( splitAt < initialSlice->begin || splitAt > initialSlice->end ) {
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return -2;
+ }
+
+ // Test before act because we'll change values of the initialSlice because
+ // it would become the firstSlice or even the second one if the first is zero-lenght
+ splitAfterSingularity=(splitAt != initialSlice->end);
+ splitBeforeSingularity=(splitAt != initialSlice->begin) && (statusBefore != statusAt);
+
+ if ( splitAfterSingularity ) {
+ thirdSlice = sliceNew(splitAt+1, initialSlice->end, statusAfter, initialSlice->next);
+ if ( thirdSlice == NULL ) {
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return -1;
+ }
+
+ initialSlice->end = splitAt;
+ // No status change because we'll split again in 2 parts or not
+ initialSlice->next = thirdSlice;
+ if ( initialSlice == slices->last ) slices->last = thirdSlice;
+ (slices->count)++;
+
+ rightSlice=thirdSlice;
+ } else {
+ rightSlice=initialSlice->next;
+ }
+
+ if ( splitBeforeSingularity ) {
+ secondSlice = sliceNew(splitAt, splitAt, statusAt, rightSlice);
+ if ( secondSlice == NULL ) {
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return -1;
+ }
+
+ initialSlice->end = splitAt-1;
+ initialSlice->status=statusBefore;
+ initialSlice->next = secondSlice;
+ if ( initialSlice == slices->last ) slices->last = secondSlice;
+ (slices->count)++;
+ } else {
+ initialSlice->status=statusAt; // Two cases : a==splitAt or statusAt==statusBefore
+ }
+
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return 1 + (splitBeforeSingularity?1:0) + (splitAfterSingularity?1:0);
+}
+
+void sliceDumpUpdate(char *dump, slice_t *s, address_t blockSize, unsigned int charCount, address_t begin, address_t end) {
+ address_t sb,se,i;
+ char ci;
+
+ // If "s" slice is (partially) contained/visible in the [begin,end] display interval
+ if ( !(s->end < begin) && !(s->begin > end) ) {
+ // Draw the slice on the right number of characters
+ // Mathematically correct, but crashes because address_t is UNSIGNED
+ // sb=MAX(0, (s->begin - begin) / *blockSize);
+ sb=(s->begin < begin)?0:(s->begin - begin) / blockSize;
+ se=MIN((s->end - begin) / blockSize, charCount-1);
+
+ /* Debug "assertion"
+ if (sb >= charCount || se >= charCount) {
+ printf("BUG : sb==%lli, se=%lli, charCount==%i\n", sb, se, charCount);
+ printf("BUG : MAX(0, (%lli - %lli) / %lli)", s->begin, begin, blockSize);
+ exit(42);
+ }*/
+
+ // Choose from the sent slice status the right char to draw
+ switch (s->status) {
+ case S_UNKNOWN: ci='_'; break;
+ case S_UNREADABLE: ci='!'; break;
+ case S_RECOVERED: ci='.'; break;
+ default: ci='~'; break;
+ }
+
+ // Draw on the right number of characters, paying attention with information collision
+ for (i=sb;i<=se;i++) {
+ if (dump[i] == ' ' ) {
+ // This is a new information
+ dump[i]=ci;
+ } else if ( dump[i] == ci || dump[i] == '!' ) {
+ // Already the right information or error, don't modify
+ } else {
+ // Multiple information on the same character
+ dump[i]='#';
+ }
+ }
+ }
+}
+
+slices_t *slicesNewEmpty() {
+ int res;
+ slices_t *ss = malloc(1*sizeof(slices_t));
+
+ if (ss==NULL) {
+ return NULL;
+ }
+
+ memset(ss, 0, sizeof(slices_t));
+ res=pthread_mutex_init(&(ss->writeOrConsistentReadMutex), NULL);
+ if (res!=0) {
+ free(ss);
+ return NULL;
+ }
+
+ return ss;
+}
+
+slices_t *slicesNewSingleton(address_t begin, address_t end, sliceStatus_t status) {
+ slice_t *s=NULL;
+ slices_t *ss = slicesNewEmpty();
+ if (ss==NULL) {
+ return NULL;
+ }
+ s=sliceNew(begin,end,status,NULL);
+ if (s==NULL) {
+ free(ss);
+ return NULL;
+ }
+ slicesAppend(ss,s);
+
+ return ss;
+}
+
+void slicesDelete(slices_t *ss) {
+ slice_t *curr, *toFree;
+
+ curr=ss->first;
+ while (curr!=NULL) {
+ toFree=curr;
+ curr=curr->next;
+ sliceDelete(toFree);
+ }
+ free(ss);
+}
+
+void slicesAppend(slices_t *slices, slice_t *slice) {
+ pthread_mutex_lock(&(slices->writeOrConsistentReadMutex));
+
+ slice->next=NULL; //XXX Could be generalized
+ if (slices->first==NULL || slices->last==NULL) {
+ slices->first = slice;
+ } else {
+ slices->last->next=slice;
+ }
+ slices->last=slice;
+ (slices->count)++;
+
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+}
+
+slice_t *slicesFindLargest(slices_t *slices, sliceStatus_t status) {
+ slice_t *curr, *sMax = NULL;
+ address_t i, iMax = 0;
+
+ pthread_mutex_lock(&(slices->writeOrConsistentReadMutex));
+
+ curr = slices->first;
+ while (curr != NULL) {
+ i=curr->end - curr->begin + 1;
+ if ( curr->status == status && i > iMax ) {
+ iMax = i;
+ sMax = curr;
+ }
+ curr=curr->next;
+ }
+
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return sMax;
+}
+
+slice_t *slicesFindLargestFast(slices_t *slices, address_t *foundMax, sliceStatus_t status, address_t knownMax, slice_t *firstToTry) {
+ slice_t *curr, *sMax = NULL;
+ address_t i, iMax = 0;
+
+//FIXME : pthread_lock à faire avant l'appel là :-s (car argument firstToTry peut pointer vers n'importe quoi si autre thread modifie
+ curr = firstToTry;
+ while (curr != NULL) {
+ i=curr->end - curr->begin + 1;
+ if ( curr->status == status ) {
+ if ( knownMax == i ) { *foundMax=i; return curr; }
+ if ( i > iMax ) {
+ iMax = i;
+ sMax = curr;
+ }
+ }
+ curr=curr->next;
+ }
+ curr = slices->first;
+ while (curr != firstToTry) {
+ i=curr->end - curr->begin + 1;
+ if ( curr->status == status && i > iMax ) {
+ iMax = i;
+ sMax = curr;
+ }
+ curr=curr->next;
+ }
+ *foundMax=iMax;
+ return sMax;
+}
+
+char *slicesDump(slices_t *slices, address_t *blockSize, unsigned int charCount, address_t begin, address_t end) {
+ int res;
+ slice_t *curr;
+ char *dump;
+
+ res=pthread_mutex_lock(&(slices->writeOrConsistentReadMutex));
+ if (res!=0) {
+ //FIXME Trashy code
+ perror("slicesDump, pb lock mutex");
+ exit(42);
+ }
+
+ // If blockSize is 0, try to autodetect to display entire slice chain
+ if (*blockSize == 0) {
+ *blockSize=(end-begin+1)/(charCount-1);
+ // If we have a too big zoom factor, draw it at 1:1 scale
+ if (*blockSize==0) *blockSize=1;
+ }
+
+ dump = malloc(charCount+1);
+ if (dump==NULL) { return NULL; }
+ memset(dump, ' ', charCount);
+ dump[charCount]=0;
+
+ //For each slice write in dump ASCII representation
+ curr = slices->first;
+ while (curr != NULL) {
+ sliceDumpUpdate(dump, curr, *blockSize, charCount, begin, end);
+ curr=curr->next;
+ }
+
+ pthread_mutex_unlock(&(slices->writeOrConsistentReadMutex));
+ return dump;
+}
+