batcher.cpp

#include "batcher.h"
#include <cstring>

JsonBatcher::JsonBatcher(char* buf, int cap)
  : buffer(buf), capacity(cap), batchCount(0) {}

void JsonBatcher::begin() {
  int n = snprintf(buffer, capacity, "{\"rows\":[");
  if (n < 0 || n >= capacity) {
    LOGE("❌ Failed to init batch buffer");
    buffer[0] = '\0';
  }
  batchCount = 0;
}

bool JsonBatcher::appendRow(const char* rowJson) {
  int curLen = strlen(buffer);
  int rowLen = strlen(rowJson);

  int extraComma = (batchCount > 0) ? 1 : 0;
  int suffixLen = strlen(BATCH_SUFFIX);

  if (curLen + extraComma + rowLen + suffixLen + 1 >= capacity) {
    return false;
  }

  if (batchCount > 0) {
    buffer[curLen] = ',';
    buffer[curLen + 1] = '\0';
    curLen++;
  }

  strncat(buffer, rowJson, capacity - curLen - 1);
  batchCount++;
  return true;
}

bool JsonBatcher::finalize(int& outLen) {
  int curLen = strlen(buffer);
  int suffixLen = strlen(BATCH_SUFFIX);
  if (curLen + suffixLen + 1 >= capacity) return false;

  strncat(buffer, BATCH_SUFFIX, capacity - curLen - 1);
  outLen = strlen(buffer);
  return true;
}