perf(io): avoid reopening v2 files during indexing

src/ikv.c

@@ -225,6 +225,29 @@ static bool read_file_prefix(const char *path, uint8_t *prefix, size_t prefix_ca
     return true;
 }
 
+static bool open_file_with_prefix(const char *path, FILE **out_file, uint8_t *prefix, size_t prefix_capacity, size_t *out_size)
+{
+    FILE *file = NULL;
+    size_t size = 0u;
+
+    if (!path || !out_file || !prefix || prefix_capacity == 0u || !out_size)
+        return false;
+
+    *out_file = NULL;
+    *out_size = 0u;
+    prefix[0] = 0u;
+
+    file = IKV_FOPEN(path, "rb");
+    if (!file)
+        return false;
+
+    size = IKV_FREAD(prefix, 1u, prefix_capacity - 1u, file);
+    prefix[size] = 0u;
+    *out_file = file;
+    *out_size = size;
+    return true;
+}
+
 static char *ikv_strdup(const char *s)
 {
     if (!s)
@@ -2279,16 +2302,38 @@ ikv_node_t *ikv_parse_string_version(const char *src, ikv_version_t version)
 
 ikv_node_t *ikv_parse_file(const char *path)
 {
+    FILE *file = NULL;
     uint8_t prefix[16] = {0};
     size_t prefix_size = 0u;
     ikv_version_t version = IKV_VERSION_UNKNOWN;
 
-    if (!read_file_prefix(path, prefix, sizeof(prefix), &prefix_size))
+    if (!open_file_with_prefix(path, &file, prefix, sizeof(prefix), &prefix_size))
         return NULL;
 
     version = ikv_detect_binary_version(prefix, prefix_size);
     if (version != IKV_VERSION_UNKNOWN)
+    {
+        ikv_node_t *root = NULL;
+
+        if (version == IKV_VERSION_2)
+        {
+            if (IKV_FSEEK(file, 0L, SEEK_SET) != 0)
+            {
+                IKV_FCLOSE(file);
+                return NULL;
+            }
+
+            root = ikv2_parse_binary_stream(file);
+            if (!root)
+                IKV_FCLOSE(file);
+            return root;
+        }
+
+        IKV_FCLOSE(file);
         return ikvb_parse_file_version(path, version);
+    }
+
+    IKV_FCLOSE(file);
 
     version = ikv_detect_text_version((const char *)prefix);
     if (version == IKV_VERSION_UNKNOWN)
@@ -2355,10 +2400,38 @@ ikv_node_t *ikvb_parse_memory_version(const void *data, size_t size, ikv_version
 
 ikv_node_t *ikvb_parse_file(const char *path)
 {
+    FILE *file = NULL;
+    uint8_t prefix[16] = {0};
+    size_t prefix_size = 0u;
     ikv_version_t version = ikv_detect_file_version(path, true);
 
-    if (version == IKV_VERSION_UNKNOWN)
+    if (!open_file_with_prefix(path, &file, prefix, sizeof(prefix), &prefix_size))
         return NULL;
+
+    version = ikv_detect_binary_version(prefix, prefix_size);
+    if (version == IKV_VERSION_UNKNOWN)
+    {
+        IKV_FCLOSE(file);
+        return NULL;
+    }
+
+    if (version == IKV_VERSION_2)
+    {
+        ikv_node_t *root = NULL;
+
+        if (IKV_FSEEK(file, 0L, SEEK_SET) != 0)
+        {
+            IKV_FCLOSE(file);
+            return NULL;
+        }
+
+        root = ikv2_parse_binary_stream(file);
+        if (!root)
+            IKV_FCLOSE(file);
+        return root;
+    }
+
+    IKV_FCLOSE(file);
     return ikvb_parse_file_version(path, version);
 }
 

src/loaders/ikv2.c

@@ -774,9 +774,8 @@ static bool ikv2_write_binary_file(const char *path, const ikv_node_t *root)
     return ok;
 }
 
-static ikv_node_t *ikv2_parse_binary_file(const char *path)
+ikv_node_t *ikv2_parse_binary_stream(FILE *file)
 {
-    FILE *file = NULL;
     uint8_t magic[4];
     uint8_t kind = 0u;
     uint32_t version = 0u;
@@ -788,10 +787,6 @@ static ikv_node_t *ikv2_parse_binary_file(const char *path)
     long file_size_long = 0;
     size_t file_size = 0u;
 
-    if (!path)
-        return NULL;
-
-    file = IKV_FOPEN(path, "rb");
     if (!file)
         return NULL;
 
@@ -919,6 +914,24 @@ static ikv_node_t *ikv2_parse_binary_file(const char *path)
     return root;
 }
 
+static ikv_node_t *ikv2_parse_binary_file(const char *path)
+{
+    FILE *file = NULL;
+    ikv_node_t *root = NULL;
+
+    if (!path)
+        return NULL;
+
+    file = IKV_FOPEN(path, "rb");
+    if (!file)
+        return NULL;
+
+    root = ikv2_parse_binary_stream(file);
+    if (!root)
+        IKV_FCLOSE(file);
+    return root;
+}
+
 static ikv_node_t *ikv2_parse_binary_memory(const void *data, size_t size)
 {
     uint8_t *buffer = NULL;

src/loaders/ikv2.h

@@ -3,3 +3,5 @@
 #include "../internal/ikv_internal.h"
 
 extern const ikv_loader_t ikv_loader_v2;
+
+ikv_node_t *ikv2_parse_binary_stream(FILE *file);