This library provides facilities to read streams into buffers. It
maintains a couple of static buffers and provides an API to use them.
Signed-off-by: David Barr <david.barr@xxxxxxxxxxxx>
Signed-off-by: Ramkumar Ramachandra <artagnon@xxxxxxxxx>
---
vcs-svn/line_buffer.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++
vcs-svn/line_buffer.h | 14 +++++
2 files changed, 143 insertions(+), 0 deletions(-)
create mode 100644 vcs-svn/line_buffer.c
create mode 100644 vcs-svn/line_buffer.h
diff --git a/vcs-svn/line_buffer.c b/vcs-svn/line_buffer.c
new file mode 100644
index 0000000..740676d
--- /dev/null
+++ b/vcs-svn/line_buffer.c
@@ -0,0 +1,129 @@
+#include "git-compat-util.h"
+
+#include "line_buffer.h"
+#include "obj_pool.h"
+
+#define LINE_BUFFER_LEN 10000
+#define COPY_BUFFER_LEN 4096
+
+/* Create memory pool for char sequence of known length */
+obj_pool_gen(blob, char, 4096);
+
+static char line_buffer[LINE_BUFFER_LEN];
+static char byte_buffer[COPY_BUFFER_LEN];
+static uint32_t line_buffer_len = 0;
+static uint32_t line_len = 0;
+static FILE *infile;
+
+int buffer_init(char *filename)
+{
+ infile = fopen(filename, "r");
+ if (!infile)
+ return 1;
+ return 0;
+}
+
+int buffer_deinit()
+{
+ fclose(infile);
+ return 0;
+}
+
+char *buffer_read_line(void)
+{
+ char *end;
+ uint32_t n_read;
+
+ if (line_len) {
+ memmove(line_buffer, &line_buffer[line_len],
+ line_buffer_len - line_len);
+ line_buffer_len -= line_len;
+ line_len = 0;
+ }
+
+ end = memchr(line_buffer, '\n', line_buffer_len);
+ while (line_buffer_len < LINE_BUFFER_LEN - 1 &&
+ !feof(infile) && ferror(infile) && NULL == end) {
+ n_read = fread(&line_buffer[line_buffer_len], 1,
+ LINE_BUFFER_LEN - 1 - line_buffer_len,
+ infile);
+ end = memchr(&line_buffer[line_buffer_len], '\n', n_read);
+ line_buffer_len += n_read;
+ }
+
+ if (ferror(infile))
+ return NULL;
+
+ if (end != NULL) {
+ line_len = end - line_buffer;
+ line_buffer[line_len++] = '\0';
+ } else {
+ line_len = line_buffer_len;
+ line_buffer[line_buffer_len] = '\0';
+ }
+
+ if (line_len == 0)
+ return NULL;
+
+ return line_buffer;
+}
+
+char *buffer_read_string(uint32_t len)
+{
+ char *s;
+ blob_free(blob_pool.size);
+ s = blob_pointer(blob_alloc(len + 1));
+ uint32_t offset = 0;
+ if (line_buffer_len > line_len) {
+ offset = line_buffer_len - line_len;
+ if (offset > len)
+ offset = len;
+ memcpy(s, &line_buffer[line_len], offset);
+ line_len += offset;
+ }
+ if (offset < len)
+ offset += fread(&s[offset], 1, len - offset, infile);
+ s[offset] = '\0';
+ return s;
+}
+
+void buffer_copy_bytes(uint32_t len)
+{
+ uint32_t in;
+ if (line_buffer_len > line_len) {
+ in = line_buffer_len - line_len;
+ if (in > len)
+ in = len;
+ fwrite(&line_buffer[line_len], 1, in, stdout);
+ len -= in;
+ line_len += in;
+ }
+ while (len > 0 && !feof(infile)) {
+ in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
+ in = fread(byte_buffer, 1, in, infile);
+ len -= in;
+ fwrite(byte_buffer, 1, in, stdout);
+ }
+}
+
+void buffer_skip_bytes(uint32_t len)
+{
+ uint32_t in;
+ if (line_buffer_len > line_len) {
+ in = line_buffer_len - line_len;
+ if (in > len)
+ in = len;
+ line_len += in;
+ len -= in;
+ }
+ while (len > 0 && !feof(infile) && !ferror(infile)) {
+ in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
+ in = fread(byte_buffer, 1, in, infile);
+ len -= in;
+ }
+}
+
+void buffer_reset(void)
+{
+ blob_reset();
+}
diff --git a/vcs-svn/line_buffer.h b/vcs-svn/line_buffer.h
new file mode 100644
index 0000000..a6c42d7
--- /dev/null
+++ b/vcs-svn/line_buffer.h
@@ -0,0 +1,14 @@
+#ifndef LINE_BUFFER_H_
+#define LINE_BUFFER_H_
+
+#include <stdint.h>
+
+int buffer_init(char *filename);
+int buffer_deinit(void);
+char *buffer_read_line(void);
+char *buffer_read_string(uint32_t len);
+void buffer_copy_bytes(uint32_t len);
+void buffer_skip_bytes(uint32_t len);
+void buffer_reset(void);
+
+#endif
--
1.7.1
--
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