1、【增加】两个读取Flash Log的方法。

Signed-off-by: armink <armink.ztl@gmail.com>

README.md

@@ -19,7 +19,7 @@ EasyLogger是一款超轻量级(ROM<1.6K, RAM<0.3k)、高性能的C日志库，
 1、RAW格式：未经过格式化的原始日志。
 2、标签：在软件中可以按照文件、模块、功能等方面，对需要打印的日志设定标签，实现日志分类。
 
-## 1.2 支持的插件
+## 1.2 插件
 
 - 1. Flash Log: 使用[EasyFlash](https://github.com/armink/EasyFlash)库提供的无缝接口，可以把日志直接存储在Flash中。
 

easylogger/inc/elog_flash.h

@@ -34,11 +34,13 @@ extern "C" {
 /* EasyLogger flash save plugin's RAM buffer size */
 #define ELOG_FLASH_BUF_SIZE                  1024
 /* EasyLogger flash save plugin's software version number */
-#define ELOG_FLASH_SW_VERSION                "0.06.09"
+#define ELOG_FLASH_SW_VERSION                "0.06.10"
 
 /* elog_flash.c */
 ElogErrCode elog_flash_init(void);
+void elog_flash_outout(size_t pos, size_t size);
 void elog_flash_outout_all(void);
+void elog_flash_outout_recent(size_t size);
 void elog_flash_set_filter(uint8_t level,const char *tag,const char *keyword);
 void elog_flash_write(const char *log, size_t size);
 void elog_flash_clean(void);

easylogger/src/elog_flash.c

@@ -66,34 +66,46 @@ ElogErrCode elog_flash_init(void) {
 }
 
 /**
- * Read and output all log which saved in flash. @note It will use filter. @see elog_flash_set_filter
+ * Read and output log which saved in flash.
+ *
+ * @param index index for saved log.
+ *        Minimum index is 0.
+ *        Maximum index is log used flash total size - 1.
+ * @param size
  */
-void elog_flash_outout_all(void) {
+void elog_flash_outout(size_t index, size_t size) {
     /* 128 bytes buffer */
     uint32_t buf[32] = { 0 };
     size_t log_total_size = flash_log_get_used_size();
     size_t buf_szie = sizeof(buf);
     size_t read_size = 0, read_overage_size = 0;
 
+    if (index + size > log_total_size) {
+        log_i("The output position and size is out of bound. The max size is %d.", log_total_size);
+        return;
+    }
+
     /* must be call this function after initialize OK */
     ELOG_ASSERT(init_ok);
     /* lock flash log buffer */
     elog_flash_port_lock();
     /* Output all flash saved log. It will use filter */
     while (true) {
-        if (read_size + buf_szie < log_total_size) {
-            flash_log_read(read_size, buf, buf_szie);
+        if (index + read_size + buf_szie < log_total_size) {
+            flash_log_read(index + read_size, buf, buf_szie);
             elog_flash_port_output((const char*)buf, buf_szie);
             read_size += buf_szie;
         } else {
             /* flash read is word alignment */
-            if ((log_total_size - read_size) % 4 == 0) {
+            if ((log_total_size - index - read_size) % 4 == 0) {
                 read_overage_size = 0;
             } else {
-                read_overage_size = 4 - ((log_total_size - read_size) % 4);
+                read_overage_size = 4 - ((log_total_size - index - read_size) % 4);
             }
-            flash_log_read(read_size, buf, log_total_size - read_size + read_overage_size);
-            elog_flash_port_output((const char*)buf, log_total_size - read_size);
+            flash_log_read(index + read_size - read_overage_size, buf,
+                    log_total_size - index - read_size + read_overage_size);
+            elog_flash_port_output((const char*) buf + read_overage_size,
+                    log_total_size - index - read_size);
             //TODO CRLF <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫͳһ<CDB3><D2BB>ͷ<EFBFBD>ļ<EFBFBD><C4BC>궨<EFBFBD><EAB6A8>
             elog_flash_port_output("\r\n", 2);
             break;
@@ -103,6 +115,27 @@ void elog_flash_outout_all(void) {
     elog_flash_port_unlock();
 }
 
+/**
+ * Read and output all log which saved in flash.
+ */
+void elog_flash_outout_all(void) {
+    elog_flash_outout(0, flash_log_get_used_size());
+}
+
+/**
+ * Read and output recent log which saved in flash.
+ *
+ * @param size recent log size
+ */
+void elog_flash_outout_recent(size_t size) {
+    size_t max_size = flash_log_get_used_size();
+    if (size > max_size) {
+        log_i("The output size is out of bound. The max size is %d.", max_size);
+    } else {
+        elog_flash_outout(max_size - size, size);
+    }
+}
+
 /**
  * Write log to flash. The flash write use buffer mode.
  *