Merge branch 'release/1.0.x'

thibaultmeyer · Oct 2, 2021 · e53f37c · e53f37c
2 parents c46be77 + 32f340f
commit e53f37c
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Showing 5 changed files with 35 additions and 16 deletions.
diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 # libsnowflakeid
 
-[![Latest release](https://img.shields.io/badge/latest_release-1.0.1-orange.svg)](https://github.com/thibaultmeyer/libsnowflakeid/releases)
+[![Latest release](https://img.shields.io/badge/latest_release-1.0.2-orange.svg)](https://github.com/thibaultmeyer/libsnowflakeid/releases)
 [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/thibaultmeyer/libsnowflakeid/blob/master/LICENSE)
 [![CodeFactor](https://www.codefactor.io/repository/github/thibaultmeyer/libsnowflakeid/badge)](https://www.codefactor.io/repository/github/thibaultmeyer/libsnowflakeid)
 
@@ -22,7 +22,11 @@ clang or MSVC are being correctly installed.
 ```c
 int main(const int argc, const char *const *argv) {
     enum e_snowflakeid_init_status     status_out;
-    struct s_snowflakeid_generator_ctx *ctx = snowflakeid_initialize(datacenter_id, worker_id, &status_out);
+    struct s_snowflakeid_generator_ctx *ctx = snowflakeid_initialize(
+            datacenter_id,
+            worker_id,
+            offset_time_ms,
+            &status_out);
 
     if (status_out == SNOWFLAKEID_INIT_SUCCESS) {
         uint64_t id = snowflakeid_next_value(ctx);

diff --git a/src/libsnowflakeid.h b/src/libsnowflakeid.h
@@ -60,6 +60,7 @@ typedef enum e_snowflakeid_init_status {
  */
 typedef struct s_snowflakeid_generator_ctx {
     uint64_t           last_time_ms;
+    uint64_t           offset_time_ms;
     uint8_t            datacenter_id;
     uint8_t            worker_id;
     uint16_t           sequence_number;
@@ -76,27 +77,29 @@ void snowflakeid_destroy(struct s_snowflakeid_generator_ctx *ctx);
 /**
  * Returns the SnowflakeID library version as a number.
  *
- * @return the SnowflakeID library version as a number (ie: 100)
+ * @return The SnowflakeID library version as a number (ie: 100)
  */
 int snowflakeid_get_version_as_int(void);
 
 /**
  * Returns the SnowflakeID library version as a string.
  *
- * @return the SnowflakeID library version as a string (ie: 1.0.0)
+ * @return The SnowflakeID library version as a string (ie: 1.0.0)
  */
 const char *snowflakeid_get_version_as_str(void);
 
 /**
  * Initialize Snowflake ID generator context.
  *
- * @param datacenter_id [IN] The Datacenter ID (Max. value = 32)
- * @param worker_id     [IN] The Worker ID (Max. value = 32)
- * @param status_out    [OUT] The operation status (ie: SNOWFLAKEID_INIT_SUCCESS)
+ * @param datacenter_id  [IN] The Datacenter ID (Max. value = 32)
+ * @param worker_id      [IN] The Worker ID (Max. value = 32)
+ * @param offset_time_ms [IN] Offset in milliseconds to be subtracted from the real "current time"
+ * @param status_out     [OUT] The operation status (ie: SNOWFLAKEID_INIT_SUCCESS)
  * @return Initialized Snowflake ID generator context, or NULL in case of error
  */
 struct s_snowflakeid_generator_ctx *snowflakeid_initialize(uint8_t datacenter_id,
                                                            uint8_t worker_id,
+                                                           uint64_t offset_time_ms,
                                                            enum e_snowflakeid_init_status *status_out);
 
 /**

diff --git a/src/snowflakeid_initialize.c b/src/snowflakeid_initialize.c
@@ -3,6 +3,7 @@
 
 struct s_snowflakeid_generator_ctx *snowflakeid_initialize(const uint8_t datacenter_id,
                                                            const uint8_t worker_id,
+                                                           const uint64_t offset_time_ms,
                                                            enum e_snowflakeid_init_status *status_out) {
     // Verify datacenter_id and worker_id
     if (datacenter_id > 31 || worker_id > 31) {
@@ -41,6 +42,7 @@ struct s_snowflakeid_generator_ctx *snowflakeid_initialize(const uint8_t datacen
 
     // Configure ctx
     ctx->last_time_ms    = 0;
+    ctx->offset_time_ms  = offset_time_ms;
     ctx->datacenter_id   = datacenter_id;
     ctx->worker_id       = worker_id;
     ctx->sequence_number = 0;

diff --git a/src/snowflakeid_next_value.c b/src/snowflakeid_next_value.c
@@ -2,7 +2,7 @@
 
 #ifdef _WIN32
 
-static inline uint64_t get_current_time_ms(void) {
+static inline uint64_t get_current_time_ms(const uint64_t *const offset_time_ms) {
     static const ULONGLONG epoch_offset_us = 116444736000000000ULL;
     FILETIME               filetime;
     ULARGE_INTEGER         x;
@@ -15,38 +15,39 @@ static inline uint64_t get_current_time_ms(void) {
     x.LowPart  = filetime.dwLowDateTime;
     x.HighPart = filetime.dwHighDateTime;
 
-    return ((x.QuadPart - epoch_offset_us) / 10000);
+    return (((x.QuadPart - epoch_offset_us) / 10000) - *offset_time_ms);
 }
 
 #else
 
-static inline uint64_t get_current_time_ms(void) {
+static inline uint64_t get_current_time_ms(const uint64_t *const offset_time_ms) {
     struct timeval tv = {0};
     gettimeofday(&tv, NULL);
 
-    return ((tv.tv_sec * 1000) + (tv.tv_usec / 1000));
+    return ((tv.tv_sec * 1000) + (tv.tv_usec / 1000) - *offset_time_ms);
 }
 
 #endif
 
-static inline uint64_t get_next_time_ms(const uint64_t *const not_until_time_ms) {
+static inline uint64_t get_next_time_ms(const uint64_t *const not_until_time_ms,
+                                        const uint64_t *const offset_time_ms) {
     uint64_t current_time_ms;
 
     do {
-        current_time_ms = get_current_time_ms();
+        current_time_ms = get_current_time_ms(offset_time_ms);
     } while (*not_until_time_ms == current_time_ms);
 
     return current_time_ms;
 }
 
 uint64_t snowflakeid_next_value(s_snowflakeid_generator_ctx *const ctx) {
-    uint64_t current_time_ms = get_current_time_ms();
+    uint64_t current_time_ms = get_current_time_ms(&ctx->offset_time_ms);
 
     SNOWFLAKEID_LOCK_WAIT_FOR(ctx->internal_lock);
     if (ctx->last_time_ms == current_time_ms) {
         ctx->sequence_number = (ctx->sequence_number + 1) % SNOWFLAKEID_SEQUENCE_MAX;
         if (ctx->sequence_number == 0) {
-            current_time_ms = get_next_time_ms(&ctx->last_time_ms);
+            current_time_ms = get_next_time_ms(&ctx->last_time_ms, &ctx->offset_time_ms);
         }
     } else {
         ctx->sequence_number = 0;

diff --git a/test/test_main.c b/test/test_main.c
@@ -4,6 +4,10 @@
 #include <string.h>
 #include "../src/libsnowflakeid.h"
 
+#define DATACENTER_ID_VALUE     5
+#define WORKER_ID_VALUE         1
+#define OFFSET_TIME_MS_VALUE    0
+
 #ifdef _WIN32
 static inline uint64_t get_current_time_ms(void) {
     static const ULONGLONG epoch_offset_us = 116444736000000000ULL;
@@ -33,7 +37,12 @@ static inline uint64_t get_current_time_ms(void) {
 
 int main(const int argc, const char *const *argv) {
     enum e_snowflakeid_init_status     status_out;
-    struct s_snowflakeid_generator_ctx *ctx = snowflakeid_initialize(5, 1, &status_out);
+    struct s_snowflakeid_generator_ctx *ctx = snowflakeid_initialize(
+            DATACENTER_ID_VALUE,
+            WORKER_ID_VALUE,
+            OFFSET_TIME_MS_VALUE,
+            &status_out);
+
     if (ctx == NULL) {
         printf("Can't create CTX: %d\n", status_out);
         return (-1);