From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 25 Sep 2023 21:05:21 +0000 (+0900)
Subject: sd-journal: drop redundant re-reading of entry array object
X-Git-Tag: v255-rc1~10^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f6548f053d29542d5f640d0d5bf2dca68e808c24;p=thirdparty%2Fsystemd.git

sd-journal: drop redundant re-reading of entry array object

This effectively reverts e562f131585fe6ae32b1f035ba48c1548d695259.

In the loop of the generic_array_bisect(), the offset of the entry array
object is unchanged, the object is read at the beginning of the loop, and
we do not read any other entry array object. Hence, it is not necessary to
re-read the object every time we use the object.
---

diff --git a/src/libsystemd/sd-journal/journal-file.c b/src/libsystemd/sd-journal/journal-file.c
index 334a28f9486..4091336c3d1 100644
--- a/src/libsystemd/sd-journal/journal-file.c
+++ b/src/libsystemd/sd-journal/journal-file.c
@@ -2877,8 +2877,8 @@ enum {
 
 static int generic_array_bisect_one(
                 JournalFile *f,
-                uint64_t a, /* offset of entry array object. */
-                uint64_t i, /* index of the entry item we will test. */
+                Object *array, /* entry array object */
+                uint64_t i,    /* index of the entry item in the array we will test. */
                 uint64_t needle,
                 int (*test_object)(JournalFile *f, uint64_t p, uint64_t needle),
                 direction_t direction,
@@ -2886,21 +2886,17 @@ static int generic_array_bisect_one(
                 uint64_t *right,
                 uint64_t *ret_offset) {
 
-        Object *array;
         uint64_t p;
         int r;
 
         assert(f);
+        assert(array);
         assert(test_object);
         assert(left);
         assert(right);
         assert(*left <= i);
         assert(i <= *right);
 
-        r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &array);
-        if (r < 0)
-                return r;
-
         p = journal_file_entry_array_item(f, array, i);
         if (p <= 0)
                 r = -EBADMSG;
@@ -2998,7 +2994,7 @@ static int generic_array_bisect(
                         return 0;
 
                 right--;
-                r = generic_array_bisect_one(f, a, right, needle, test_object, direction, &left, &right, &lp);
+                r = generic_array_bisect_one(f, array, right, needle, test_object, direction, &left, &right, &lp);
                 if (r == -ENOANO) {
                         n = right;
                         continue;
@@ -3012,13 +3008,13 @@ static int generic_array_bisect(
                          * neighbors of the last index we looked at. */
 
                         if (last_index > 0 && last_index - 1 < right) {
-                                r = generic_array_bisect_one(f, a, last_index - 1, needle, test_object, direction, &left, &right, NULL);
+                                r = generic_array_bisect_one(f, array, last_index - 1, needle, test_object, direction, &left, &right, NULL);
                                 if (r < 0 && r != -ENOANO)
                                         return r;
                         }
 
                         if (last_index < right) {
-                                r = generic_array_bisect_one(f, a, last_index + 1, needle, test_object, direction, &left, &right, NULL);
+                                r = generic_array_bisect_one(f, array, last_index + 1, needle, test_object, direction, &left, &right, NULL);
                                 if (r < 0 && r != -ENOANO)
                                         return r;
                         }
@@ -3035,7 +3031,7 @@ static int generic_array_bisect(
                                 assert(left < right);
                                 i = (left + right) / 2;
 
-                                r = generic_array_bisect_one(f, a, i, needle, test_object, direction, &left, &right, NULL);
+                                r = generic_array_bisect_one(f, array, i, needle, test_object, direction, &left, &right, NULL);
                                 if (r < 0 && r != -ENOANO)
                                         return r;
                         }
@@ -3065,10 +3061,6 @@ found:
         if (subtract_one && t == 0 && i == 0)
                 return 0;
 
-        r = journal_file_move_to_object(f, OBJECT_ENTRY_ARRAY, a, &array);
-        if (r < 0)
-                return r;
-
         p = journal_file_entry_array_item(f, array, 0);
         if (p <= 0)
                 return -EBADMSG;