{"id":8771,"url":"https://patchwork.libcamera.org/api/1.1/patches/8771/?format=json","web_url":"https://patchwork.libcamera.org/patch/8771/","project":{"id":1,"url":"https://patchwork.libcamera.org/api/1.1/projects/1/?format=json","name":"libcamera","link_name":"libcamera","list_id":"libcamera_core","list_email":"libcamera-devel@lists.libcamera.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20200714090936.9562-1-laurent.pinchart@ideasonboard.com>","date":"2020-07-14T09:09:33","name":"[libcamera-devel,v2,1/4] libcamera: file: Add read/write support","commit_ref":"25288281d1e72c8e6c264525926a200511407ac7","pull_url":null,"state":"accepted","archived":false,"hash":"37180e69b057badc56d3cc8fbbae8f8f583a683b","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/1.1/people/2/?format=json","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"delegate":null,"mbox":"https://patchwork.libcamera.org/patch/8771/mbox/","series":[{"id":1103,"url":"https://patchwork.libcamera.org/api/1.1/series/1103/?format=json","web_url":"https://patchwork.libcamera.org/project/libcamera/list/?series=1103","date":"2020-07-14T09:09:33","name":"[libcamera-devel,v2,1/4] libcamera: file: Add read/write support","version":2,"mbox":"https://patchwork.libcamera.org/series/1103/mbox/"}],"comments":"https://patchwork.libcamera.org/api/patches/8771/comments/","check":"pending","checks":"https://patchwork.libcamera.org/api/patches/8771/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 02C8ABD790\n\tfor ;\n\tTue, 14 Jul 2020 09:09:49 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 6D34C607BD;\n\tTue, 14 Jul 2020 11:09:48 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 2F8BF60483\n\tfor ;\n\tTue, 14 Jul 2020 11:09:47 +0200 (CEST)","from pendragon.bb.dnainternet.fi (81-175-216-236.bb.dnainternet.fi\n\t[81.175.216.236])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id AD788564\n\tfor ;\n\tTue, 14 Jul 2020 11:09:46 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"ieu+jSUb\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1594717786;\n\tbh=/QsgrHKm13Gr5qOL7fK0z3kLpCEXUBZJipLsV/Rpo6E=;\n\th=From:To:Subject:Date:From;\n\tb=ieu+jSUblAbujoE7Xi4WtivR5KMUFEEWOj8Pi1UjQBTZWek+OliQFrrAJPg/ZtigK\n\tjUGSghQ/I76ngp8p/la4+LpZRvIb/Dd5Ax501tAztl4f0CyggWYUDgVqRlRR56Na28\n\tYfKNUIebSw8edd/Sha2RVo7OqFZnjKwUnAVA99LE=","From":"Laurent Pinchart ","To":"libcamera-devel@lists.libcamera.org","Date":"Tue, 14 Jul 2020 12:09:33 +0300","Message-Id":"<20200714090936.9562-1-laurent.pinchart@ideasonboard.com>","X-Mailer":"git-send-email 2.27.0","MIME-Version":"1.0","Subject":"[libcamera-devel] [PATCH v2 1/4] libcamera: file: Add read/write\n\tsupport","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "},"content":"Add basic support to read and write data from/to a file, along with\nretrieving and setting the current read/write position.\n\nSigned-off-by: Laurent Pinchart \nReviewed-by: Kieran Bingham \n---\nChanges since v1:\n\n- Don't cache pos(), use lseek()\n---\n include/libcamera/internal/file.h | 6 ++\n src/libcamera/file.cpp | 109 ++++++++++++++++++++++++++++++\n 2 files changed, 115 insertions(+)","diff":"diff --git a/include/libcamera/internal/file.h b/include/libcamera/internal/file.h\nindex e3e72132e336..9b6d011f5e9d 100644\n--- a/include/libcamera/internal/file.h\n+++ b/include/libcamera/internal/file.h\n@@ -49,6 +49,12 @@ public:\n \tint error() const { return error_; }\n \tssize_t size() const;\n \n+\toff_t pos() const;\n+\toff_t seek(off_t pos);\n+\n+\tssize_t read(const Span &data);\n+\tssize_t write(const Span &data);\n+\n \tSpan map(off_t offset = 0, ssize_t size = -1,\n \t\t\t MapFlag flags = MapNoOption);\n \tbool unmap(uint8_t *addr);\ndiff --git a/src/libcamera/file.cpp b/src/libcamera/file.cpp\nindex c471bde3fc68..d99a1806e1c8 100644\n--- a/src/libcamera/file.cpp\n+++ b/src/libcamera/file.cpp\n@@ -237,6 +237,115 @@ ssize_t File::size() const\n \treturn st.st_size;\n }\n \n+/**\n+ * \\brief Return current read or write position\n+ *\n+ * If the file is closed, this function returns 0.\n+ *\n+ * \\return The current read or write position\n+ */\n+off_t File::pos() const\n+{\n+\tif (!isOpen())\n+\t\treturn 0;\n+\n+\treturn lseek(fd_, 0, SEEK_CUR);\n+}\n+\n+/**\n+ * \\brief Set the read or write position\n+ * \\param[in] pos The desired position\n+ * \\return The resulting offset from the beginning of the file on success, or a\n+ * negative error code otherwise\n+ */\n+off_t File::seek(off_t pos)\n+{\n+\tif (!isOpen())\n+\t\treturn -EINVAL;\n+\n+\toff_t ret = lseek(fd_, pos, SEEK_SET);\n+\tif (ret < 0)\n+\t\treturn -errno;\n+\n+\treturn ret;\n+}\n+\n+/**\n+ * \\brief Read data from the file\n+ * \\param[in] data Memory to read data into\n+ *\n+ * Read at most \\a data.size() bytes from the file into \\a data.data(), and\n+ * return the number of bytes read. If less data than requested is available,\n+ * the returned byte count may be smaller than the requested size. If no more\n+ * data is available, 0 is returned.\n+ *\n+ * The position of the file as returned by pos() is advanced by the number of\n+ * bytes read. If an error occurs, the position isn't modified.\n+ *\n+ * \\return The number of bytes read on success, or a negative error code\n+ * otherwise\n+ */\n+ssize_t File::read(const Span &data)\n+{\n+\tif (!isOpen())\n+\t\treturn -EINVAL;\n+\n+\tsize_t readBytes = 0;\n+\tssize_t ret = 0;\n+\n+\t/* Retry in case of interrupted system calls. */\n+\twhile (readBytes < data.size()) {\n+\t\tret = ::read(fd_, data.data() + readBytes,\n+\t\t\t data.size() - readBytes);\n+\t\tif (ret <= 0)\n+\t\t\tbreak;\n+\n+\t\treadBytes += ret;\n+\t}\n+\n+\tif (ret < 0 && !readBytes)\n+\t\treturn -errno;\n+\n+\treturn readBytes;\n+}\n+\n+/**\n+ * \\brief Write data to the file\n+ * \\param[in] data Memory containing data to be written\n+ *\n+ * Write at most \\a data.size() bytes from \\a data.data() to the file, and\n+ * return the number of bytes written. If the file system doesn't have enough\n+ * space for the data, the returned byte count may be less than requested.\n+ *\n+ * The position of the file as returned by pos() is advanced by the number of\n+ * bytes written. If an error occurs, the position isn't modified.\n+ *\n+ * \\return The number of bytes written on success, or a negative error code\n+ * otherwise\n+ */\n+ssize_t File::write(const Span &data)\n+{\n+\tif (!isOpen())\n+\t\treturn -EINVAL;\n+\n+\tsize_t writtenBytes = 0;\n+\n+\t/* Retry in case of interrupted system calls. */\n+\twhile (writtenBytes < data.size()) {\n+\t\tssize_t ret = ::write(fd_, data.data() + writtenBytes,\n+\t\t\t\t data.size() - writtenBytes);\n+\t\tif (ret <= 0)\n+\t\t\tbreak;\n+\n+\t\twrittenBytes += ret;\n+\t}\n+\n+\tif (data.size() && !writtenBytes)\n+\t\treturn -errno;\n+\n+\treturn writtenBytes;\n+}\n+\n /**\n * \\brief Map a region of the file in the process memory\n * \\param[in] offset The region offset within the file\n","prefixes":["libcamera-devel","v2","1/4"]}