From b2802a37aaa132a6e31c0859df122f0eef3a6f9e Mon Sep 17 00:00:00 2001
From: Martin Preuss <martin@aquamaniac.de>
Date: Wed, 25 Jun 2025 00:00:39 +0200
Subject: [PATCH] added AQH_Storage_GetFirstNDataPoints()

---
 aqhome/data/storage.c   | 72 +++++++++++++++++++++++++++++++++++++++++
 aqhome/data/storage.h   |  6 ++++
 aqhome/data/storage_p.h |  1 +
 3 files changed, 79 insertions(+)

diff --git a/aqhome/data/storage.c b/aqhome/data/storage.c
index 74a8a65..70faf46 100644
--- a/aqhome/data/storage.c
+++ b/aqhome/data/storage.c
@@ -305,6 +305,17 @@ AQH_STORAGE_GETLASTDATAPOINT_FN AQH_Storage_SetGetLastDatapointFn(AQH_STORAGE *s
 
 
 
+AQH_STORAGE_GETFIRSTNDATAPOINTS_FN AQH_Storage_SetGetFirstNDatapointsFn(AQH_STORAGE *sto, AQH_STORAGE_GETFIRSTNDATAPOINTS_FN fn)
+{
+  AQH_STORAGE_GETFIRSTNDATAPOINTS_FN oldFn;
+
+  oldFn=sto->getFirstNDatapointsFn;
+  sto->getFirstNDatapointsFn=fn;
+  return oldFn;
+}
+
+
+
 AQH_STORAGE_GETLASTNDATAPOINTS_FN AQH_Storage_SetGetLastNDatapointsFn(AQH_STORAGE *sto, AQH_STORAGE_GETLASTNDATAPOINTS_FN fn)
 {
   AQH_STORAGE_GETLASTNDATAPOINTS_FN oldFn;
@@ -468,6 +479,67 @@ uint64_t *AQH_Storage_GetDataPoints(AQH_STORAGE *sto, uint64_t valueId, uint64_t
 
 
 
+uint64_t *AQH_Storage_GetFirstNDataPoints(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested)
+{
+  AQH_DATAFILE *df;
+  uint64_t numEntries;
+  uint64_t numOfDataEntries;
+  uint64_t arrayLen;
+  uint64_t arrayPos;
+  uint64_t *arrayPtr;
+  uint64_t firstRecord;
+  uint64_t i;
+
+  df=_getDataFileByValueId(sto, valueId);
+  if (df==NULL) {
+    DBG_ERROR(AQH_LOGDOMAIN, "No file for value id %lu", (unsigned long int) valueId);
+    return NULL;
+  }
+  numEntries=AQH_DataFile_GetNumberOfEntries(df);
+  numOfDataEntries=numEntries-1;              /* first entry is reserved, don't count it here */
+  if (numOfDataEntries<1) {
+    DBG_INFO(AQH_LOGDOMAIN, "No data records for value id %lu", (unsigned long int) valueId);
+    return NULL;
+  }
+  firstRecord=1;
+  if (numOfDataEntries>maxDataPointsRequested)   /* more entries in file than requested */
+    arrayLen=(maxDataPointsRequested*2)+1;       /* +1 because the first array entry contains the number of entries */
+  else
+    arrayLen=(numOfDataEntries*2)+1;
+
+  arrayPtr=(uint64_t*) malloc(arrayLen*sizeof(uint64_t));
+  if (arrayPtr==NULL) {
+    DBG_ERROR(AQH_LOGDOMAIN, "Not enough memory for %lu entries", (unsigned long int) arrayLen);
+    return NULL;
+  }
+  arrayPos=1;
+
+  for (i=firstRecord; i<numEntries; i++) {
+    union {double f; uint64_t i;} u;
+    uint64_t ts;
+    int rv;
+
+    rv=AQH_DataFile_ReadRecord(df, i, &ts, &(u.f));
+    if (rv<0) {
+      DBG_ERROR(AQH_LOGDOMAIN, "here (%d)", rv);
+      free(arrayPtr);
+      return NULL;
+    }
+
+    if ((arrayPos+1)>=arrayLen) {
+      DBG_INFO(AQH_LOGDOMAIN, "Requested number of entries reached");
+      break;
+    }
+    arrayPtr[arrayPos++]=ts;
+    arrayPtr[arrayPos++]=u.i;
+  } /* for */
+
+  arrayPtr[0]=arrayPos-1;
+  return arrayPtr;
+}
+
+
+
 uint64_t *AQH_Storage_GetLastNDataPoints(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested)
 {
   AQH_DATAFILE *df;
diff --git a/aqhome/data/storage.h b/aqhome/data/storage.h
index c23152f..d30b257 100644
--- a/aqhome/data/storage.h
+++ b/aqhome/data/storage.h
@@ -53,6 +53,8 @@ typedef uint64_t *(*AQH_STORAGE_GETDATAPOINTS_FN)(AQH_STORAGE *sto, uint64_t val
 						  uint64_t maxArrayLen);
 typedef int (*AQH_STORAGE_GETFIRSTDATAPOINT_FN)(AQH_STORAGE *sto, uint64_t valueId, uint64_t *pTimestamp, double *pValue);
 typedef int (*AQH_STORAGE_GETLASTDATAPOINT_FN)(AQH_STORAGE *sto, uint64_t valueId, uint64_t *pTimestamp, double *pValue);
+
+typedef uint64_t *(*AQH_STORAGE_GETFIRSTNDATAPOINTS_FN)(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested);
 typedef uint64_t *(*AQH_STORAGE_GETLASTNDATAPOINTS_FN)(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested);
 
 
@@ -96,6 +98,8 @@ AQHOME_API uint64_t *AQH_Storage_GetDataPoints(AQH_STORAGE *sto, uint64_t valueI
                                                uint64_t maxArrayLen);
 AQHOME_API int AQH_Storage_GetFirstDataPoint(AQH_STORAGE *sto, uint64_t valueId, uint64_t *pTimestamp, double *pValue);
 AQHOME_API int AQH_Storage_GetLastDataPoint(AQH_STORAGE *sto, uint64_t valueId, uint64_t *pTimestamp, double *pValue);
+
+AQHOME_API uint64_t *AQH_Storage_GetFirstNDataPoints(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested);
 AQHOME_API uint64_t *AQH_Storage_GetLastNDataPoints(AQH_STORAGE *sto, uint64_t valueId, uint64_t maxDataPointsRequested);
 
 
@@ -105,6 +109,8 @@ AQHOME_API AQH_STORAGE_ADDDATAPOINT_FN AQH_Storage_SetAddDatapointFn(AQH_STORAGE
 AQHOME_API AQH_STORAGE_GETDATAPOINTS_FN AQH_Storage_SetGetDatapointsFn(AQH_STORAGE *sto, AQH_STORAGE_GETDATAPOINTS_FN fn);
 AQHOME_API AQH_STORAGE_GETFIRSTDATAPOINT_FN AQH_Storage_SetGetFirstDatapointFn(AQH_STORAGE *sto, AQH_STORAGE_GETFIRSTDATAPOINT_FN fn);
 AQHOME_API AQH_STORAGE_GETLASTDATAPOINT_FN AQH_Storage_SetGetLastDatapointFn(AQH_STORAGE *sto, AQH_STORAGE_GETLASTDATAPOINT_FN fn);
+
+AQHOME_API AQH_STORAGE_GETFIRSTNDATAPOINTS_FN AQH_Storage_SetGetFirstNDatapointsFn(AQH_STORAGE *sto, AQH_STORAGE_GETFIRSTNDATAPOINTS_FN fn);
 AQHOME_API AQH_STORAGE_GETLASTNDATAPOINTS_FN AQH_Storage_SetGetLastNDatapointsFn(AQH_STORAGE *sto, AQH_STORAGE_GETLASTNDATAPOINTS_FN fn);
 
 
diff --git a/aqhome/data/storage_p.h b/aqhome/data/storage_p.h
index 0cc5701..c8cad6b 100644
--- a/aqhome/data/storage_p.h
+++ b/aqhome/data/storage_p.h
@@ -47,6 +47,7 @@ struct AQH_STORAGE {
   AQH_STORAGE_GETFIRSTDATAPOINT_FN getFirstDatapointFn;
   AQH_STORAGE_GETLASTDATAPOINT_FN getLastDatapointFn;
   AQH_STORAGE_GETLASTNDATAPOINTS_FN getLastNDatapointsFn;
+  AQH_STORAGE_GETFIRSTNDATAPOINTS_FN getFirstNDatapointsFn;
 };