From e779642091e567828fa06213c163618b0dd65b0b Mon Sep 17 00:00:00 2001
From: adam <anton@adamansky.com>
Date: Mon, 29 Oct 2012 13:10:50 +0700
Subject: [PATCH] Fix query skip bug + test case

---
 tcejdb/ejdb.c        | 29 +++++++++++++++++++++--------
 tcejdb/testejdb/t2.c | 41 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 60 insertions(+), 10 deletions(-)

diff --git a/tcejdb/ejdb.c b/tcejdb/ejdb.c
index a973728..9f5768e 100644
--- a/tcejdb/ejdb.c
+++ b/tcejdb/ejdb.c
@@ -1286,7 +1286,7 @@ static TCLIST* _qrysearch(EJCOLL *jcoll, const EJQ *q, uint32_t *outcount, int q
         for (int i = 0; i < ofsz; ++i) assert(ofs[i] != NULL);
     }
 
-    if (!onlycount && aofsz > 0 && (!midx || mqf->orderseq != 1)) { //Main index is not main order field
+    if (!onlycount && aofsz > 0 && (!midx || mqf->orderseq != 1)) { //Main index is not the main order field
         all = true; //Need all records for ordering for some other fields
     }
 
@@ -1315,7 +1315,7 @@ static TCLIST* _qrysearch(EJCOLL *jcoll, const EJQ *q, uint32_t *outcount, int q
 
 #define JBQREGREC(_bsbuf, _bsbufsz)   \
     ++count; \
-    if (!onlycount && count > skip) { \
+    if (!onlycount && (all || count > skip)) { \
         TCLISTPUSH(res, _bsbuf, _bsbufsz); \
     } \
     if (_bsbuf) { \
@@ -1690,12 +1690,25 @@ finish:
     if (max < UINT_MAX && max > skip) {
         max = max - skip;
     }
-    if (res && TCLISTNUM(res) > max) { //truncate resulting list if max specified
-        int end = res->start + res->num;
-        TCLISTDATUM *array = res->array;
-        for (int i = (res->start + max); i < end; i++) {
-            TCFREE(array[i].ptr);
-            --(res->num);
+    if (res) {
+        if (all) { //skipping results after full sorting with skip > 0
+            for (int i = 0; i < skip && res->num > 0; ++i) {
+                TCFREE(res->array[res->start].ptr);
+                ++(res->start);
+                --(res->num);
+            }
+        }
+        if ((res->start & 0xff) == 0 && res->start > (res->num >> 1)) {
+            memmove(res->array, res->array + res->start, res->num * sizeof (res->array[0]));
+            res->start = 0;
+        }
+        if (TCLISTNUM(res) > max) { //truncate results if max specified
+            int end = res->start + res->num;
+            TCLISTDATUM *array = res->array;
+            for (int i = (res->start + max); i < end; i++) {
+                TCFREE(array[i].ptr);
+                --(res->num);
+            }
         }
     }
     count = (skip < count) ? count - skip : 0;
diff --git a/tcejdb/testejdb/t2.c b/tcejdb/testejdb/t2.c
index fb176d2..f9e86eb 100644
--- a/tcejdb/testejdb/t2.c
+++ b/tcejdb/testejdb/t2.c
@@ -1902,7 +1902,7 @@ void testQuery24() {
     bson bshints;
     bson_init_as_query(&bshints);
     bson_append_start_object(&bshints, "$orderby");
-    bson_append_int(&bshints, "name", -1); //DESC order on dblscore
+    bson_append_int(&bshints, "name", -1); //DESC order on name
     bson_append_finish_object(&bshints);
     bson_append_long(&bshints, "$skip", 1);
     bson_finish(&bshints);
@@ -1947,7 +1947,7 @@ void testQuery24() {
 
     bson_init_as_query(&bshints);
     bson_append_start_object(&bshints, "$orderby");
-    bson_append_int(&bshints, "name", -1); //DESC order on dblscore
+    bson_append_int(&bshints, "name", -1); //DESC order on name
     bson_append_finish_object(&bshints);
     bson_append_long(&bshints, "$skip", 1);
     bson_append_long(&bshints, "$max", 2);
@@ -2061,6 +2061,43 @@ void testQuery24() {
     tclistdel(q1res);
     tcxstrdel(log);
     ejdbquerydel(q1);
+
+
+    bson_init_as_query(&bsq1);
+    bson_finish(&bsq1);
+    CU_ASSERT_FALSE_FATAL(bsq1.err);
+
+    bson_init_as_query(&bshints);
+    bson_append_start_object(&bshints, "$orderby");
+    bson_append_int(&bshints, "name", 1); //ASC
+    bson_append_finish_object(&bshints);
+    bson_append_long(&bshints, "$skip", 3);
+    bson_finish(&bshints);
+    CU_ASSERT_FALSE_FATAL(bshints.err);
+
+    q1 = ejdbcreatequery(jb, &bsq1, NULL, 0, &bshints);
+    CU_ASSERT_PTR_NOT_NULL_FATAL(q1);
+
+    count = 0;
+    log = tcxstrnew();
+    q1res = ejdbqrysearch(contacts, q1, &count, 0, log);
+    //fprintf(stderr, "%s", TCXSTRPTR(log));
+
+    CU_ASSERT_EQUAL(count, 1);
+    CU_ASSERT_TRUE(TCLISTNUM(q1res) == 1);
+
+    for (int i = 0; i < TCLISTNUM(q1res); ++i) {
+        if (i == TCLISTNUM(q1res) - 1) {
+            CU_ASSERT_FALSE(bson_compare_string("Антонов", TCLISTVALPTR(q1res, i), "name"));
+        }
+    }
+
+    bson_destroy(&bsq1);
+    bson_destroy(&bshints);
+    tclistdel(q1res);
+    tcxstrdel(log);
+    ejdbquerydel(q1);
+
 }
 
 void testQuery25() { //$or
-- 
2.7.4