[gentoo-commits] proj/steve:main commit in: src/

[Michał Górny]

commit:     b4eec8162b2d775cbc31c740991db2663fc49c32
Author:     Michał Górny <mgorny <AT> gentoo <DOT> org>
AuthorDate: Thu Dec 25 17:03:46 2025 +0000
Commit:     Michał Górny <mgorny <AT> gentoo <DOT> org>
CommitDate: Thu Dec 25 17:03:46 2025 +0000
URL:        https://gitweb.gentoo.org/proj/steve.git/commit/?id=b4eec816

Move /proc/meminfo search into a separate function

Signed-off-by: Michał Górny <mgorny <AT> gentoo.org>

 src/steve.cxx | 66 +++++++++++++++++++++++++++++++++++++----------------------
 1 file changed, 41 insertions(+), 25 deletions(-)

diff --git a/src/steve.cxx b/src/steve.cxx
index 952f72e..25a6b50 100644
--- a/src/steve.cxx
+++ b/src/steve.cxx
@@ -27,6 +27,7 @@
 #include <optional>
 #include <print>
 #include <string>
+#include <string_view>
 #include <unordered_map>
 #include <variant>
 
@@ -185,6 +186,41 @@ static void steve_get_load(steve_state *state)
        }
 }
 
+static std::optional<long> steve_get_meminfo(int fd, std::string_view label)
+{
+       char buf[4096] = {"\n"};
+       ssize_t rd = pread(fd, &buf[1], sizeof(buf) - 2, 0);
+
+       if (rd < 0) {
+               perror("Reading /proc/meminfo failed, memory use will not be 
available");
+               return {};
+       }
+
+       buf[rd + 1] = 0;
+       char *match = strstr(buf, label.data());
+       if (!match) {
+               std::print(stderr, "Parsing /proc/meminfo failed: no {}\n", 
label);
+               return {};
+       }
+       match += label.size();
+       match += strspn(match, " ");
+
+       char *end = match + strspn(match, "0123456789");
+       if (strncmp(end, " kB\n", 4)) {
+               std::print(stderr, "Parsing /proc/meminfo failed: {} not 
suffixed by ' kB'\n", label);
+               return {};
+       }
+       *end = 0;
+
+       long val;
+       if (!arg_to_long(match, &val)) {
+               std::print(stderr, "Parsing /proc/meminfo failed: {} is not a 
valid positive long\n", match);
+               return {};
+       }
+
+       return val;
+}
+
 static void steve_get_memory_use(steve_state *state)
 {
        if (state->meminfo_fd == -2) {
@@ -194,31 +230,11 @@ static void steve_get_memory_use(steve_state *state)
        }
 
        if (state->meminfo_fd != -1) {
-               char buf[4096] = {"\n"};
-               ssize_t rd = pread(state->meminfo_fd, &buf[1], sizeof(buf) - 2, 
0);
-
-               if (rd >= 0) {
-                       buf[rd + 1] = 0;
-
-                       constexpr char mem_avail_label[] = "\nMemAvailable:";
-                       char *mem_avail = strstr(buf, mem_avail_label);
-                       if (mem_avail) {
-                               mem_avail += sizeof(mem_avail_label) - 1;
-                               mem_avail += strspn(mem_avail, " ");
-                               char *end = mem_avail + strspn(mem_avail, 
"0123456789");
-                               if (!strncmp(end, " kB\n", 4)) {
-                                       *end = 0;
-                                       long val;
-                                       if (arg_to_long(mem_avail, &val)) {
-                                               state->memory_avail = val / 
1024;
-                                               return;
-                                       }
-                               }
-                       }
-
-                       std::print(stderr, "Parsing /proc/meminfo failed\n");
-               } else
-                       perror("Reading /proc/meminfo failed, memory use will 
not be available");
+               auto maybe_val = steve_get_meminfo(state->meminfo_fd, 
"\nMemAvailable:");
+               if (maybe_val.has_value()) {
+                       state->memory_avail = maybe_val.value() / 1024;
+                       return;
+               }
 
                close(state->meminfo_fd);
                state->meminfo_fd = -1;