mdbx: контроль отсутствия дубликатов LCK-файла с альтернативными именами.

mdbx.h

@@ -1932,6 +1932,9 @@ enum MDBX_error_t {
    *       равнозначна \ref MDBX_PROBLEM. */
   MDBX_BACKLOG_DEPLETED = -30414,
 
+  /** Alternative/Duplicate LCK-file is exists and should be removed manually */
+  MDBX_DUPLICATED_CLK = -30413,
+
   /* The last of MDBX-added error codes */
   MDBX_LAST_ADDED_ERRCODE = MDBX_TXN_OVERLAPPING,
 

src/core.c

@@ -3471,6 +3471,9 @@ __cold const char *mdbx_liberr2str(int errnum) {
   case MDBX_TXN_OVERLAPPING:
     return "MDBX_TXN_OVERLAPPING: Overlapping read and write transactions for"
            " the current thread";
+  case MDBX_DUPLICATED_CLK:
+    return "MDBX_DUPLICATED_CLK: Alternative/Duplicate LCK-file is exists, "
+           "please keep one and remove unused other";
   default:
     return NULL;
   }
@@ -14461,6 +14464,17 @@ typedef struct {
   size_t ent_len;
 } MDBX_handle_env_pathname;
 
+__cold static int check_alternative_lck_absent(const pathchar_t *lck_pathname) {
+  int err = osal_fileexists(lck_pathname);
+  if (unlikely(err != MDBX_RESULT_FALSE)) {
+    if (err == MDBX_RESULT_TRUE)
+      err = MDBX_DUPLICATED_CLK;
+    ERROR("Alternative/Duplicate LCK-file '%" MDBX_PRIsPATH "' error %d",
+          lck_pathname, err);
+  }
+  return err;
+}
+
 __cold static int handle_env_pathname(MDBX_handle_env_pathname *ctx,
                                       const pathchar_t *pathname,
                                       MDBX_env_flags_t *flags,
@@ -14562,23 +14576,45 @@ __cold static int handle_env_pathname(MDBX_handle_env_pathname *ctx,
     return MDBX_ENOMEM;
 
   ctx->dxb = ctx->buffer_for_free;
+  ctx->lck = ctx->dxb + ctx->ent_len + dxb_name_len + 1;
+  pathchar_t *const buf = ctx->buffer_for_free;
+  rc = MDBX_SUCCESS;
   if (ctx->ent_len) {
-    ctx->lck = ctx->dxb + ctx->ent_len + 1;
+    memcpy(buf, pathname, sizeof(pathchar_t) * pathname_len);
+    if (*flags & MDBX_NOSUBDIR) {
+      const pathchar_t *const lck_ext =
+          osal_fileext(lck_name, ARRAY_LENGTH(lck_name));
+      if (lck_ext) {
+        pathchar_t *pathname_ext = osal_fileext(buf, pathname_len);
+        memcpy(pathname_ext ? pathname_ext : buf + pathname_len, lck_ext,
+               sizeof(pathchar_t) * (ARRAY_END(lck_name) - lck_ext));
+        rc = check_alternative_lck_absent(buf);
+      }
+    } else {
+      memcpy(buf + ctx->ent_len, dxb_name, sizeof(dxb_name));
+      memcpy(buf + ctx->ent_len + dxb_name_len, lock_suffix,
+             sizeof(lock_suffix));
+      rc = check_alternative_lck_absent(buf);
+    }
+
     memcpy(ctx->dxb, pathname, sizeof(pathchar_t) * (ctx->ent_len + 1));
+    memcpy(ctx->lck, pathname, sizeof(pathchar_t) * ctx->ent_len);
     if (*flags & MDBX_NOSUBDIR) {
       memcpy(ctx->lck + ctx->ent_len, lock_suffix, sizeof(lock_suffix));
     } else {
-      ctx->lck += dxb_name_len;
-      memcpy(ctx->lck + ctx->ent_len, lck_name, sizeof(lck_name));
       memcpy(ctx->dxb + ctx->ent_len, dxb_name, sizeof(dxb_name));
+      memcpy(ctx->lck + ctx->ent_len, lck_name, sizeof(lck_name));
     }
-    memcpy(ctx->lck, pathname, sizeof(pathchar_t) * ctx->ent_len);
   } else {
-    ctx->lck = ctx->dxb + dxb_name_len;
-    memcpy(ctx->lck, lck_name + 1, sizeof(lck_name) - sizeof(pathchar_t));
+    assert(!(*flags & MDBX_NOSUBDIR));
+    memcpy(buf, dxb_name + 1, sizeof(dxb_name) - sizeof(pathchar_t));
+    memcpy(buf + dxb_name_len - 1, lock_suffix, sizeof(lock_suffix));
+    rc = check_alternative_lck_absent(buf);
+
     memcpy(ctx->dxb, dxb_name + 1, sizeof(dxb_name) - sizeof(pathchar_t));
+    memcpy(ctx->lck, lck_name + 1, sizeof(lck_name) - sizeof(pathchar_t));
   }
-  return MDBX_SUCCESS;
+  return rc;
 }
 
 __cold int mdbx_env_delete(const char *pathname, MDBX_env_delete_mode_t mode) {

src/osal.c

@@ -1185,6 +1185,33 @@ MDBX_INTERNAL_FUNC int osal_removedirectory(const pathchar_t *pathname) {
 #endif
 }
 
+MDBX_INTERNAL_FUNC int osal_fileexists(const pathchar_t *pathname) {
+#if defined(_WIN32) || defined(_WIN64)
+  if (GetFileAttributesW(pathname) != INVALID_FILE_ATTRIBUTES)
+    return MDBX_RESULT_TRUE;
+  int err = GetLastError();
+  return (err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND)
+             ? MDBX_RESULT_FALSE
+             : err;
+#else
+  if (access(pathname, F_OK) == 0)
+    return MDBX_RESULT_TRUE;
+  int err = errno;
+  return (err == ENOENT || err == ENOTDIR) ? MDBX_RESULT_FALSE : err;
+#endif
+}
+
+MDBX_INTERNAL_FUNC pathchar_t *osal_fileext(const pathchar_t *pathname,
+                                            size_t len) {
+  const pathchar_t *ext = nullptr;
+  for (size_t i = 0; i < len && pathname[i]; i++)
+    if (pathname[i] == '.')
+      ext = pathname + i;
+    else if (osal_isdirsep(pathname[i]))
+      ext = nullptr;
+  return (pathchar_t *)ext;
+}
+
 MDBX_INTERNAL_FUNC bool osal_pathequal(const pathchar_t *l, const pathchar_t *r,
                                        size_t len) {
 #if defined(_WIN32) || defined(_WIN64)

src/osal.h

@@ -225,8 +225,10 @@ osal_syspagesize(void) {
 
 #if defined(_WIN32) || defined(_WIN64)
 typedef wchar_t pathchar_t;
+#define MDBX_PRIsPATH "ls"
 #else
 typedef char pathchar_t;
+#define MDBX_PRIsPATH "s"
 #endif
 
 typedef struct osal_mmap {
@@ -559,6 +561,9 @@ MDBX_MAYBE_UNUSED static __inline bool osal_isdirsep(pathchar_t c) {
 
 MDBX_INTERNAL_FUNC bool osal_pathequal(const pathchar_t *l, const pathchar_t *r,
                                        size_t len);
+MDBX_INTERNAL_FUNC pathchar_t *osal_fileext(const pathchar_t *pathname,
+                                            size_t len);
+MDBX_INTERNAL_FUNC int osal_fileexists(const pathchar_t *pathname);
 MDBX_INTERNAL_FUNC int osal_openfile(const enum osal_openfile_purpose purpose,
                                      const MDBX_env *env,
                                      const pathchar_t *pathname,