1.1 --- a/src/buffer.c Sat Apr 30 09:03:17 2022 +0200
1.2 +++ b/src/buffer.c Sat Apr 30 09:47:20 2022 +0200
1.3 @@ -32,6 +32,7 @@
1.4 #include <stdlib.h>
1.5 #include <stdio.h>
1.6 #include <string.h>
1.7 +#include <stdint.h>
1.8
1.9 int cxBufferInit(
1.10 CxBuffer *buffer,
1.11 @@ -53,8 +54,12 @@
1.12 }
1.13 buffer->capacity = capacity;
1.14 buffer->size = 0;
1.15 + buffer->pos = 0;
1.16
1.17 - buffer->pos = 0;
1.18 + buffer->flush_func = NULL;
1.19 + buffer->flush_blkmax = 0;
1.20 + buffer->flush_blksize = 4096;
1.21 + buffer->flush_threshold = SIZE_MAX;
1.22
1.23 return 0;
1.24 }
1.25 @@ -134,6 +139,7 @@
1.26 size_t nitems,
1.27 CxBuffer *buffer
1.28 ) {
1.29 + // TODO: optimize for special case size == nitems == 1
1.30 size_t len;
1.31 if (cx_szmul(size, nitems, &len)) {
1.32 return 0;
1.33 @@ -143,15 +149,27 @@
1.34 return 0;
1.35 }
1.36
1.37 + bool perform_flush = false;
1.38 if (required > buffer->capacity) {
1.39 - if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
1.40 - if (cxBufferMinimumCapacity(buffer, required)) {
1.41 - return 0;
1.42 + if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND && required) {
1.43 + if (buffer->flush_blkmax > 0 && required > buffer->flush_threshold) {
1.44 + perform_flush = true;
1.45 + } else {
1.46 + if (cxBufferMinimumCapacity(buffer, required)) {
1.47 + return 0;
1.48 + }
1.49 }
1.50 } else {
1.51 - len = buffer->capacity - buffer->pos;
1.52 - if (size > 1) {
1.53 - len -= len % size;
1.54 + if (buffer->flush_blkmax > 0) {
1.55 + perform_flush = true;
1.56 + } else {
1.57 + // truncate data to be written, if we can neither extend nor flush
1.58 + len = buffer->capacity - buffer->pos;
1.59 + if (size > 1) {
1.60 + // TODO: this is bugged - it would only discard one element and not as many as required
1.61 + len -= len % size;
1.62 + nitems = len / size;
1.63 + }
1.64 }
1.65 }
1.66 }
1.67 @@ -160,13 +178,25 @@
1.68 return len;
1.69 }
1.70
1.71 - memcpy(buffer->bytes + buffer->pos, ptr, len);
1.72 - buffer->pos += len;
1.73 - if (buffer->pos > buffer->size) {
1.74 - buffer->size = buffer->pos;
1.75 + if (perform_flush) {
1.76 + // TODO: implement flushing
1.77 + // (1) determine how many bytes to flush (use flushmax = blkmax * blksize)
1.78 + // (2) if len is larger than the number computed in (1) we need more flush cycles, compute how many
1.79 + // (3) determine how many bytes from the buffer shall be flushed
1.80 + // (4) if something remains in the buffer, shift the buffer to the left
1.81 + // (4a) if buffer was shifted, append the new data to the buffer
1.82 + // (4b) if the buffer was flushed entirely AND the new data also fits into flushmax,
1.83 + // directly write the new data to the flush sink
1.84 + return 0; // remove this after implementation
1.85 + } else {
1.86 + memcpy(buffer->bytes + buffer->pos, ptr, len);
1.87 + buffer->pos += len;
1.88 + if (buffer->pos > buffer->size) {
1.89 + buffer->size = buffer->pos;
1.90 + }
1.91 }
1.92
1.93 - return len / size;
1.94 + return nitems;
1.95 }
1.96
1.97 int cxBufferPut(
